Polymeric Biomaterials and Bioengineering: Select Proceedings of APA Bioforum 2021 (Lecture Notes in Bioengineering) 9811910839, 9789811910838

Citation preview

Lecture Notes in Bioengineering

Bhuvanesh Gupta · Mohammad Jawaid · B. S. Kaith · Sunita Rattan · Susheel Kalia   Editors

Polymeric Biomaterials and Bioengineering Select Proceedings of APA Bioforum 2021

Lecture Notes in Bioengineering Advisory Editors Nigel H. Lovell, Graduate School of Biomedical Engineering, University of New South Wales, Kensington, NSW, Australia Luca Oneto, DIBRIS, Università di Genova, Genova, Italy Stefano Piotto, Department of Pharmacy, University of Salerno, Fisciano, Italy Federico Rossi, Department of Earth, University of Salerno, Fisciano, Siena, Italy Alexei V. Samsonovich, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA Fabio Babiloni, Department of Molecular Medicine, University of Rome Sapienza, Rome, Italy Adam Liwo, Faculty of Chemistry, University of Gdansk, Gdansk, Poland Ratko Magjarevic, Faculty of Electrical Engineering and Computing, University of Zagreb, Zagreb, Croatia

Lecture Notes in Bioengineering (LNBE) publishes the latest developments in bioengineering. It covers a wide range of topics, including (but not limited to): • • • • • • • • • • •

Bio-inspired Technology & Biomimetics Biosensors Bionanomaterials Biomedical Instrumentation Biological Signal Processing Medical Robotics and Assistive Technology Computational Medicine, Computational Pharmacology and Computational Biology Personalized Medicine Data Analysis in Bioengineering Neuroengineering Bioengineering Ethics

Original research reported in proceedings and edited books are at the core of LNBE. Monographs presenting cutting-edge findings, new perspectives on classical fields or reviewing the state-of-the art in a certain subfield of bioengineering may exceptionally be considered for publication. Alternatively, they may be redirected to more specific book series. The series’ target audience includes advanced level students, researchers, and industry professionals working at the forefront of their fields. Indexed by SCOPUS, INSPEC, zbMATH, SCImago.

More information about this series at https://link.springer.com/bookseries/11564

Bhuvanesh Gupta · Mohammad Jawaid · B. S. Kaith · Sunita Rattan · Susheel Kalia Editors

Polymeric Biomaterials and Bioengineering Select Proceedings of APA Bioforum 2021

Editors Bhuvanesh Gupta Bioengineering Laboratory Department of Textile Technology Indian Institute of Technology New Delhi, Delhi, India B. S. Kaith Department of Chemistry Dr. B. R. Ambedkar National Institute of Technology Jalandhar, Punjab, India

Mohammad Jawaid Laboratory of Biocomposite Technology Institute of Tropical Forestry and Forest Products (INTROP) Universiti Putra Malaysia Serdang, Selangor, Malaysia Sunita Rattan Amity Institute of Applied Sciences Amity University Noida, Uttar Pradesh, India

Susheel Kalia Department of Chemistry Army Cadet College Wing of Indian Military Academy Dehradun, Uttarakhand, India

ISSN 2195-271X ISSN 2195-2728 (electronic) Lecture Notes in Bioengineering ISBN 978-981-19-1083-8 ISBN 978-981-19-1084-5 (eBook) https://doi.org/10.1007/978-981-19-1084-5 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore

About the Society Involved in the Organization of This Conference

Asian Polymer Association (APA) is a professional society dedicated to the science of polymers. Asian Polymer Association (APA) was founded in 2007 at the premises of the Indian Institute of Technology New Delhi, India. The society involves academicians, scientists and technologists from all over the Asian countries providing a wellknitted structure of the society. The vision of the society is to bring together Asian Science and Technology to the forefront of the global arena so that a very dynamic association with the scientific world from Europe and America may be accomplished. The society platform will help in bring together the polymer community to a highly interactive association with each other. Society has grown as a dynamic platform at the international level with enormous collaboration with societies abroad.

v

Conference Organizers and Boards

Conference Chair Bhuvanesh Gupta, IIT Delhi, India

Conference Co-chairs Philippe Roger, UPS, Orsay, France Sunita Rattan, Amity, Noida, India M. V. Badiger, NCL, Pune, India M. S. Alam, JH, Delhi, India

Organizing Chair B. S. Kaith, NIT Jalandhar, India

Organizing Co-chairs Susheel Kalia, IMA, Dehradun, India Dhiraj Sud, SLIET, India Pankaj Attri, KU, Fukuoka, Japan Rohidas Arote, SNU, Seoul, Korea Jawaid Mohammad, INTROP, Selangor, Malaysia

vii

viii

Secretary Aditi Sangal, Amity, Noida, India

Joint Secretary Chetna Verma, IIT Delhi, India

International Advisory Committee Amédée Joëlle, INSERM, France Ahmad Ishaq, Malaysia Averous Luc, University of Strasbourg, France Celli Annamaria, University of Bologna, Italy Focarete Maria Letizia, University of Bologna, Italy Frederic Guittard, University of Nice, France Grande Daniel, CNRS, France Gupta Dipak, TU, Nepal Haraguchi Kazutoshi, Nihon University, Japan Hendrana Sunit, LIPI, Indonesia Hilborn Jöns, Uppsala, Sweden Jhurry Dhanjay, University of Mauritius Jaime Ramirez-Vick, WSU, Dayton, USA Kim W. J., Postech, Korea Kim Hern, M. University, S Korea Letourneur Didier, INSERM, France Mishra Ajay, University SA, South Africa Phinyocheep Pranee, Mahidol University, Thailand Peng Ching-An, University of Idaho, USA Ramakrishna Seeram, NUS, Singapore Singh K. P., Rohilkhand University, India Suzuki Atsushi, YNU, Japan Sanyal Amitav, B. University, Turkey Teodori Laura, ENEA, Italy

National Advisory Committee Bhowmick Shantanu, Amrita, Coimbatore

Conference Organizers and Boards

Conference Organizers and Boards

Bhan Surya, NEHU, Shillong Chauhan G. S., HP University, Shimla Gupta Amlan, SMIMS, Gangtok Gupta Virendra, RIL, Mumbai Ghildiyal Shivani, AIIA, New Delhi Ghosh A. K., IIT Delhi, India Jayakumar R., Amrita, Kochi Katiyar Vimal, IIT Guwahati Kumar Ashok, IIT Kanpur Rakesh Kumar, NIT Jalandhar Lochab Bimlesh, SN University, Noida Mishra Satyendra, NMU, Jalgaon Mukhopadhyay Samrat, IIT Delhi Mandal Biman, IIT Guwahati Mohanty Smita, CIPET, Bhubaneswar Mandal Sanjay, IISER, Mohali Mehta S. K., P University, Chandigarh Maiti Pralay, IIT BHU Nayak S. K., R. University, Cuttack Negi Poonam, S. University, HP Negi Y. S., IIT Roorkee Pathania Deepak, CUJ, Jammu Patra Shamayita, SVITT Indore Rathour J. K., GFL, Gujarat Sharma Anupama, P. University, Chandigarh Sharma Sunil, S. University, HP Singh Pradeep, S. University, HP Singh Harpal, IIT Delhi Singh Mukesh, UPTTI, Kanpur Shandilya Pooja, S. University, HP Singh S. P., NPL, Delhi Singh Narinder, IIT Ropar Singh Yeshveer, IIT Ropar Shimpy N. G., Bombay University, Mumbai Sherkhane Rahul, AIIA, New Delhi Verma RS, IIT Madras Yadav Pramod, AIIA, New Delhi

National Organizing Committee Convener: Ikram Saiqa, JMI, New Delhi Balram, NIT Jalandhar Borah Jutishna, Amity, Kolkata

ix

x

G. S. Bharat Govind, Amity University, Noida Khullar Sadhika, NIT Jalandhar Kumar Rakesh, NIT Jalandhar Kumari Vandana, IIT Delhi Nisar Safiya, Amity University, Noida Nonglang Flavius, NEHU, Shillong Rohit, NIT Jalandhar Shanker Uma, NIT Jalandhar Sharma Ankita, IIT Delhi Sharma Preeti, IIT Roorkee Singh Anjali, NIT Jalandhar Singh Pratibha, IIT Delhi Singh Surbhi, DRDO, Delhi Somani Manali, IIT Delhi Upadhyay Shiv, IIT Delhi Varade Dharmesh, A. University Ahmedabad Vipula, IIT Delhi Verma Rohini, IIT Delhi

Conference Organizers and Boards

About This Book

This book presents select proceedings of the ‘APA Bioforum International e-Conference on Polymeric Biomaterials & Bioengineering (APA Bioforum-2021)’. Health care is an integral part of human life. Polymeric biomaterials play a significant role in the fabrication of many life-saving devices. This book mainly focused on developing innovative polymeric materials for bioengineering and human healthcare systems. This book helps understand molecular architecture and its role in governing physical characteristics, which is extremely useful for understanding the biosystem’s interactions. The topics covered include polymer synthesis, biopolymers, biomaterials, smart materials, nanotechnology, scaffold designing, tissue engineering, wound care system, targeted drug delivery, antimicrobial materials, biocompatible implants, biosensors and diagnostics, bio-waste management, water decontamination and purification. The book can be a valuable reference for beginners, researchers and professionals interested in polymeric materials and biomaterials for human health care. This book includes comprehensive step-by-step chapters from the processing and functionalization of biopolymers to applications. This will help the readers to know the recent developments and comprehensive research on biopolymers for health care. All the chapters in this book have sufficient illustrations, tables, figures, graphs, bibliographies and extensive references to have comprehensive information.

xi

Contents

Biopolymeric Nanofibrous Bandage for Wound-Healing Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elakkiya Thangaraju, V. Riteshsaravanaraj, and S. D. Premkumar Preparation and Characterization of Polymer Biocomposite 3D Mat for Bone Tissue Regeneration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gurumoorthi Ramar, Bhuvana K. Periyasamy, R. Joseph Bensingh, and S. K. Nayak Growth and Spectral Features of Silver-Doped Aniline– Formaldehyde Nanocomposite Polymer: Density Functional Theory Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Anant D. Kulkarni, Giriraj Tailor, and Libero J. Bartolotti Evaluation of Machining Performance and Parametric Optimization During Drilling of Bio-nanocomposite . . . . . . . . . . . . . . . . . . Umang Dubey, Jogendra Kumar, Prakhar Kumar Kharwar, and Rajesh Kumar Verma Polymeric Lipid Nanoparticles for Donepezil Delivery . . . . . . . . . . . . . . . . Meghana Bhandari, Nahida Rasool, and Yashveer Singh

1

11

23

41

51

Role of Natural Polymers as Carriers for Targeting Cognitive Disorder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bhavna, Arpita Sahoo, and Manmohan Singhal

65

Copper(II)-Catalyzed Ring Opening Polymerization of Cyclic Esters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Isha Jain and Payal Malik

77

Screening for Polythene-Degrading Bacteria from Dumped Soil Area and Its in vitro Microbial Polythene Degradation . . . . . . . . . . . . . . . . Romana Naaz and Weqar Ahmad Siddiqi

87

xiii

xiv

Contents

Investigations on Excellent Selectivity and Performance for Removal of Anionic Azo Dyes from Wastewater Using Terephthalaldehyde Crosslinked Chitosan Copolymerized with Acrylamide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Madhvi Garg and Dhiraj Sud The Effect of the Adding of Banana Sap on the Properties of PEGDMA/PEO Hydrogel Film Sap for Wound-Healing Acceleration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Haryanto, Fena Retyo Titani, Nunuk Aries Nurulita, and Achmad Chafidz Synergistic Effect of Encapsulated Linseed Oil and Soybean Oil Blend in Phenol-Formaldehyde Microcapsule on Self-healing Efficiency of Anticorrosive Coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 P. S. Shisode, C. B. Patil, and P. P. Mahulikar Cost-Effective Synthesis of Hydroxyapatite from Waste Egg Shells and Clam Shells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Anjali Shibu, Sainul Abidh, P. V. Dennymol, and Tresa Sunitha George Neuroprotective Potential of Ayurvedic Herbal Extracts: A Promising Avenue in the Therapeutic Management of Alzheimer Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Nidhi Gupta, Ritu Verma, Alka Madaan, Kriti Soni, Anu T. Singh, Manu Jaggi, Pallavi Kushwaha, and Surinder P. Singh Formaldehyde Gas Sensor Based on MoS2 /RGO 2D/2D Functional Nanocomposites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Jyoti Gupta, Prachi Singhal, and Sunita Rattan

About the Editors

Prof. Bhuvanesh Gupta is the Professor of Polymers at Indian Institute of Technology, New Delhi and is the President of Asian Polymer Association along with other international bodies, Society of Biomaterials Artificial Organs India (Delhi), Society of Tissue Engineering & Regenerative Medicine, India and Indo-Italian Forum on Biomaterials & Tissue Engineering. Dr. Gupta did his Ph.D. from IIT Delhi and spent a couple of years as post-doc in Paris. Subsequently, Dr. Gupta worked for eight years in France, Sweden and Switzerland under different capacities in several laboratories. Dr. Gupta initiated research career in the field of polymer functionalization, biomaterials and tissue engineering and worked in collaboration with University of Uppsala, Sweden and INSERM Paris, France. At the national level, the research collaborations are with AIIMS New Delhi, PGI Chandigarh, Panjab University Chandigarh, NEHU Shillong, and Sikkim Manipal University, Gangtok. Dr. Gupta had brief assignment as Director (Research) at Sikkim Manipal University Gangtok and is back to IIT system as professor of polymers and biomaterials. Dr. Gupta is among the 2% top polymer scientists in the world and has been awarded medals at the University Level and has been granted several Visiting Fellowships in different European countries involving Sweden, Switzerland and France. He has been the member of DBT talk force of Government of India. He is on the editorial board of several journals. Winner of several awards and medals, Dr. Gupta has about 200 publications in International journals and more than 400 conference presentations in India and abroad along with 28 patents to his credit. Dr. Gupta has authored eight books published by International publishers and has been invited by several laboratories across Europe for delivering talks. With a strong support from a large number of doctorate students and scientists, the Prof. Gupta’s group is engaged in different areas of polymeric biomaterials and biomedical engineering. Prof. Mohammad Jawaid has done Ph.D. (Polymer Composites) from Universiti Sains Malaysia, Georgetown, Penang, Malaysia. Presently working as Senior Fellow (Professor) at Biocomposite Technology Laboratory, INTROP, Universiti Putra Malaysia (UPM), Serdang, Selangor, Malaysia, and also has been Visiting Professor at the Department of Chemical Engineering, College of Engineering, King xv

xvi

About the Editors

Saud University, Riyadh, Saudi Arabia since June 2013. He has more than 20 years of experience in teaching, research, and industries. His area of research interests includes hybrid composites, lignocellulosic reinforced/filled polymer composites, advance materials: graphene/nanoclay/fire retardant, modification and treatment of lignocellulosic fibres and solid wood, biopolymers and biopolymers for packaging applications, nanocomposites and nanocellulose fibres, and polymer blends. He has published 40 books, 65 book chapters, more than 350 peer-reviewed international journal papers. He is founding Series Editor of Composite Science and Technology Springer Book Series and Series Editor of Springer Proceedings in Materials. Presently, he is supervising 12 Ph.D. students and six master’s students in the fields of hybrid composites, green composites, nanocomposites, natural fiber-reinforced composites, nanocellulose, etc. He has several research grants at university, national, and international levels on polymer composites of around 3 million Malaysian ringgits (USD 700,000). He also delivered plenary and invited talks in international conferences related to composites in India, Turkey, Malaysia, Thailand, UK, France, Saudi Arabia, Egypt, and China. Dr. Mohammad Jawaid received an Excellent Academic Award in Category of International Grant-Universiti Putra Malaysia-2018 and an Excellent Academic Staff Award in industry High Impact Network (ICAN 2019) Award. Besides that Gold Medal-Community and Industry Network (JINM Showcase) at Universiti Putra Malaysia. He also Received Publons Peer Review Awards 2017, and 2018 (Materials Science), Certified Sentinel of Science Award Recipient-2016 (Materials Science) and 2019 (Materials Science and Crossfield). He is also the Winner of Newton-Ungku Omar Coordination Fund: UK-Malaysia Research and Innovation Bridges Competition 2015. Recently he was recognized with Fellow and Charted Scientist Award from the Institute of Materials, Minerals and Mining (IOM), UK. He is also life member of the Asian Polymer Association, and the Malaysian Society for Engineering and Technology. He has professional membership of American Chemical Society (ACS), and Society for polymers Engineers (SPE), USA. Prof. (HAG) B. S. Kaith joined NIT Jalandhar in 2007 as Professor of Chemistry. Before joining NIT Jalandhar, he served NIT Hamirpur for about 16 years. He was Head of Chemistry Department from September 2009 to 2012 and from January 2019 to February 2021. He also served NIT Jalandhar in the capacity of Dean Planning & Development, Registrar, Dean Students Welfare and Dean Academic. Professor Kaith also served as a member Board of Governors (BOG), NIT Jalandhar from April 2018 to April 2020. Professor Kaith also served as the Visitor’s Nominee (President of India Nominee) in the Selection Boards for the Faculty positions in Sciences in NITs from March 2017 to March 2020. Presently Prof. Kaith is Visitor’s Nominee (President of India Nominee) in Selection Board (Chemistry) to IIT Mandi (HP). Dr Kaith is ranked among the Top 2% Scientists of the World as per the survey conducted by Stanford University, USA. Presently his research group is working on Smart Materials and their applications in sustained/controlled drug delivery systems, controlled release of agrochemicals, removal of toxic dyes and heavy metal ions from the contaminated water etc. He is also working on the modification of fibers through

About the Editors

xvii

graft copolymerization and nanogel composites. He has published more than 250 research papers in international journals of repute (SCI & Scopus indexed). He has produced 25 Ph.D. students and four are currently in progress. His citation index is as follows: Citations: 7788, h-index = 42 and i10-Index = 142. He is the recipient of ICC award 2018, NIT Jalandhar Best Teacher Award 2018, HIM Science Congress Fellow of the year Award 2013–2014, NIT Hamirpur Commendation Award 2003. ICASNew Delhi Chapter (IOC) Excellence in Science Award. In addition, his research group got the Golden paper award, Young Chemist Award, Young Scientist Awards and Best Paper Awards. Prof. Sunita Rattan is Dean, Science & Technology and Director, Amity Institute of Applied Sciences, Amity University Uttar Pradesh, Noida, India. She has held many administrative and academic positions throughout her career. She has a rich experience of 25 years in Academics and Research. She is the fellow of Royal Society of Chemistry, London. Her research areas include polymer grafting, ion beam modifications, stimulus responsive polymeric membranes, chemiresistive sensors, nanomaterials, nanocomposites, and membranes for selective separation. She has published more than 65 research papers in reputed international journals and presented around 70 papers in national and international conferences. She has given more than 25 invited talks at various international conferences. She has filed 15 patents out of which four are granted and three are in pipeline at the final stages of being awarded She has edited a number of books and has contributed chapters in the books with publishers like Royal Society of Chemistry, Springer and Nova publishers. She has funded projects from reputed funding organizations including DRDO, DST, IUAC, BRNS, SERB and two from International agencies such as Inter Atomic Energy Association, Austria. In addition to her above assignments, she is serving as secretary Asian Polymer Association and Society for Biomaterials & Artificial Organs (Delhi). Dr. Susheel Kalia is an Associate Professor and Head in the Department of Chemistry at Army Cadet College Wing of Indian Military Academy Dehradun, India. He was awarded GOC-in-C Commendation Card by General Officer Commanding-inChief, Army Training Command, Shimla on 26 January 2018 for a positive approach, high level of motivation, outstanding qualities of leadership and sincerity towards the organization. Dr. Kalia has been recognized as the top 2% among scientists in the field of Polymer Science by Stanford University, USA. He was a Postdoc Researcher in 2013 and was selected as a visiting Professor for the year 2020– 2021 at the University of Bologna, Italy. Kalia has around 90 research articles in international journals along with 20 books, 11 book chapters and more than 9200 citations with 43 h-index in his academic career. He has guided many M.Phil. and Ph.D. students and delivered many invited talks at national and international conferences. His research interests include polymeric bio- and nanocomposites, surface modification, conducting polymers, nanofibers, nanoparticles, nanoferrites, hybrid materials and hydrogels. Kalia is an experienced book editor, and he has edited a number of successful books with Springer & Wiley. Kalia is the main editor of the

xviii

About the Editors

Springer Series on Polymer and Composite Materials, Springer International Publication, Switzerland and an editorial board member of the International Journal of Plastic Technology, Springer, India. In addition, he is a member of a number of professional organizations, including the Asian Polymer Association, Indian Cryogenics Council, the Society for Polymer Science, the Indian Society of Analytical Scientists, and the International Association of Advanced Materials.

Biopolymeric Nanofibrous Bandage for Wound-Healing Applications Elakkiya Thangaraju , V. Riteshsaravanaraj, and S. D. Premkumar

1 Introduction In India, traditional wound care treatment is the primary approach due to low cost and easily available in the kitchen [1, 2]. The level of wounds is increased means the cotton, gauge, dressing materials, bandage are used for the treatment due to its affordability and simply accessible in the market [3]. The quick and good healing is more significant in the treatment of severe burn wounds especially diabetic patients. The wound-curing process involves an interaction between epidermal and dermal cells, extracellular matrix, controlled angiogenesis and plasma-derived proteins— all synchronized by the collection of cytokines and growth factors [4]. The porous surface formations gives enough cell-seeding density within the nanofibrous bandage and also makes possible to free transport of nutrients and oxygen for effective cell proliferation and differentiation [5]. The electrospinning process is simple, scalable technology to fabricate the nanofibrous bandage which is similar to native extracellular matrix protein structure [6]. The electrospun nanofibrous bandage gives even adherence, high gas permeation, exuding fluid from the wound, protection from infection and dehydration as compared to other type of wound-dressing materials [7–9]. The biopolymers especially hydrogel-like polymers are giving special attention in the field of wound healing due to its unique properties such as control the dosage of drug, absorb and prevent loss of body fluids [10, 11]. Polyvinylpyrrolidone (PVP) is a water-soluble, biodegradable, hydrophilic, Food and Drug Administration (FDA) approved polymer which is mainly used for biomedical applications [12, 13]. PVP is E. Thangaraju (B) PG & Research Department of Chemistry, Sri Sarada College for Women (Autonomous), Salem, Tamilnadu 636016, India V. Riteshsaravanaraj Murugia Dental Care, Sri Sarada College Road, Fairlands, Salem, Tamilnadu 636016, India S. D. Premkumar Bharathirajaa Hospital and Research Centre Private Limited, Chennai, Tamilnadu 600017, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_1

1

2

E. Thangaraju et al.

considered as a convenient polymer for wound dressing due to its similarity of living tissue, soft rubbery consistency, chemical stability and water-absorption capability [14]. The fabrication of thin film-like structure of PVP is suitable to act as carrier for pharmaceutical applications due to its unique properties [15, 16]. In addition, PVP is also used for blood detoxifier and temporary skin bandage [17]. The woundhealing process is one of the complicated and delayed ones for diabetic patients. For the diabetic ulcer patients, the proper dressing is most important to prevent the wound from the microorganisms and environmental dust. The advantages of incorporation of antibacterial active compound into biopolymer nanofibrous bandage are not only it kills the bacteria but also it feels like soft and comfortable to wear [18, 19]. The bitter melon pulp extract incorporation gives advantageous biological properties to the prepared polycaprolactone/polyvinyl alcohol/collagen nanofibrous membrane for wound care [20]. The electrospun berberine-incorporated cellulose acetate and gelatin blend dressing materials enhance the healing process of diabetic foot ulcer [21]. Generally, the silver nanoparticles to be used in wound-healing applications have received much attention because of their excellent antibacterial property [22]. The silver nanoparticles doped collagen-alginate antimicrobial biocomposite as possible wound-dressing material [23]. The electrospun silver nanoparticles-loaded polyvinyl alcohol) nanofibrous bandage acts as an effective barrier for wounds and the invading pathogens [24]. The turmeric powder is mainly used for food stuff and natural medicine in the developing countries like India and China for many centuries. Curcumin is one of the best organic compounds extracted from Curcuma Longa L which is also known as turmeric. Curcumin is used to cure many diseases due to the presence of bioactive polyphenol compound [25, 26]. The curcumin market growth will exceed by 100 million dollars at 2024 according to the recent report by Global Market Insights Inc. The curcumin is extracted and used mainly for pharmaceuticals due to its excellent antibacterial, antioxidant, anti-cancer, anti-fertility, antifungal, anti-inflammatory and antiviral properties [27]. The present study mainly focuses on the combination of rich antibacterial property of silver nanoparticles and curcumin that were dispersed in the PVP surface and fabricate the bioactive nanofibrous bandage for diabetic ulcer patients.

2 Experimental 2.1 Materials Polyvinylpyrrolidone (average molecular weight 360,000) was purchased from Sigma Aldrich, India. Silver nitrate was purchased from Merck, India. Curcuma Longa L was cultivated from Salem, India. Phyllanthus Niruri was purchased from local market, Salem, India. Ethanol and acetone were purchased from Sisco Research Laboratories Private Limited, India. Distilled water and all other chemicals are used for all analysis without further purification.

Biopolymeric Nanofibrous Bandage for Wound-Healing Applications

3

2.2 Methods The Phyllanthus Niruri leaves were washed carefully to remove impurities using distilled water. The leaves’ extract was poured dropwise into the prepared 0.01M aqueous silver nitrate solution under static condition and incubated at 37 °C for 15 min. After 15 min, the solution colour was turned into brown-yellow which was the indication of formation of silver nanoparticles [28]. Curcumin was extracted from Curcuma Longa L using ethanol as solvent by Soxhlet apparatus technique [29]. The equal ratio (1:1 ratio) of prepared silver nanoparticles and curcumin in ethanol was added in to the aqueous 8 wt.% PVP homogeneous solution at room temperature and stirred continuously for 5 h using magnetic stirrer. Then, the above solution was sonicated at 15 min. The prepared homogeneous solution was taken in a 5 ml plastic disposable syringe and connected to the positive charge. The negative terminal was connected to the drum collector which was wrapped with aluminium foil. The high electric voltage was applied, and the polymer solution was converted to nanofibres due to its electrostatic condition. The polymer-based solution was electrospun and optimized the flow rate at 1 ml/h, electric voltage at 28 kV and needle tip to drum collector distance at 13 cm. The detailed electrospinning process was reported earlier [30].

2.3 Characterization The prepared silver nanoparticles and curcumin absorbance was observed using the double-beam UV–visible spectrophotometer, Cyber Lab. The silver nanoparticles and curcumin dispersion on PVP surface was studied by transmission electron microscopy (TEM-TF 20: Tecnai) operating at 200 kV. The antibacterial activity of the electrospun nanofibrous bandages was studied by well-diffusion method [31]. The cytotoxicity test was performed by MTT {3-(4,5-dimethylthiazole-2-yl)-2,5diphenyl tetrazolium} assay using mouse embryonic fibroblast (NIH 3T3) cell lines [32]. The surface morphology of the electrospun nanofibrous bandage after seeded on NIH 3T3 cell lines at 72 h of incubation was studied by high-resolution scanning electron microscope (HRSEM–FEI Quanta FEG 200) with an accelerating voltage of 5–20 kV.

4

E. Thangaraju et al.

Fig. 1 UV spectrum of a Silver nanoparticles, b Curcumin

3 Results and Discussion 3.1 UV–Visible Spectroscopy and Transmission Electron Microscopy The synthesized silver nanoparticles from Phyllanthus Niruri extract were identified by UV–visible absorption spectrophotometer. The absorption peak at 425 nm confirms the formation of silver nanoparticles as shown in Fig. 1a [33]. The curcumin extraction from Curcuma Longa L absorbance was observed by UV–visible spectrophotometer as shown in Fig. 1b. The curcumin was well extracted and was identified by the absorption peak at 423 nm. Therefore, the UV–visible spectra results confirmed that the silver particles were in the nanorange and curcumin was absolutely extracted. The surface morphology of the fabricated nanofibrous bandage was analysed by transmission electron microscopy (TEM). The dispersion of silver nanoparticles and curcumin within the surface of the nanofibres was more clearly observed in Fig. 2. The average fibre diameter was found to be approximately in the range of 100 nm. Hence, the TEM results confirm that the dispersion of silver nanoparticles and curcumin in the PVP nanofibres was more suitable for the wound-healing applications.

3.2 Antibacterial Activity The antibacterial activity of the electrospun PVP, curcumin-PVP (Cur-PVP), silver nanoparticles-Curcumin-PVP (AgNps-Cur-PVP) nanofibrous bandages was evaluated using the standard drug Gentamicin (20 µg). The antibacterial activity of the prepared nanofibrous bandage was tested against two gram-positive (Staphylococcus

Biopolymeric Nanofibrous Bandage for Wound-Healing Applications

5

Fig. 2 Transmission electron microscopic image of the electrospun silver nanoparticles-curcumindispersed PVP

aureus and Bacillus subtilis) and two gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. PVP is a biocompatible polymer with no antibacterial activity, while the electrospun AgNps-Curcumin-PVP nanofibrous bandage shows good antibacterial activity due to the presence of silver nanoparticles and curcumin. The electrospun AgNps-Cur-PVP nanofibrous bandage shows better zone of inhibition compared to Cur-PVP nanofibrous bandage as shown in Fig. 3. The molecular interactions of drug and polymer complex were explained in detail [34, 35]. Hence, the electrospun AgNps-Cur-PVP nanofibrous bandage antibacterial studies confirm the suitability of wound-healing applications (Table 1).

3.3 Cytotoxicity Test The cytotoxicity test of the electrospun PVP and AgNps-Cur-PVP nanofibrous bandages was evaluated at 24, 48 and 72 h incubation period by MTT assay using mouse embryonic fibroblast (NIH 3T3) cell lines. The electrospun PVP nanofibrous bandage shows more than 100% cell viability after 72 h of incubation. The electrospun AgNps-Cur-PVP nanofibrous bandage was found to be non-toxic, good cell attachment and proliferation rate as shown in Fig. 4a, b Generally, the electrospun nanofibrous bandage surface was similar to human extracellular matrix protein structure. The SEM image proves that the cell growth properly occurs on the surface of the electrospun nanofibrous bandage without affecting the healthy cells. Hence, the biocompatibility of the electrospun AgNps-Cur-PVP nanofibrous bandage was good and may be used for wound-healing applications.

6

E. Thangaraju et al.

Fig. 3 Antibacterial activity of the electrospun nanofibrous bandage, a Bacillus subtilis, b Staphylococcus aureus, c Escherichia coli and d Pseudomonas aeruginosa (i) Cur-PVP (ii) AgNps-Cur-PVP (iii) PVP and (iv) Control

Table 1 Zone of inhibition (mm) of the electrospun nanofibrous bandage Sample code

Bacillus subtilis

Staphylococcus aureus

Escherichia coli

Pseudomonas aeruginosa

Cur-PVP

15

16

16

10

AgNps-Cur-PVP

20

21

18

18

PVP

-

-

-

-

Gentamicin (20 µg)

21

23

21

23

4 Conclusion The silver nanoparticles and curcumin were synthesized and confirmed by UV– visible spectroscopy. The silver nanoparticles and curcumin were successfully dispersed on the PVP nanofibres, and fabricated nanofibrous bandage by electrospinning method was confirmed by TEM. The suitability of the fabricated electrospun AgNps-Cur-PVP nanofibrous bandage for wound–healing applications was

Biopolymeric Nanofibrous Bandage for Wound-Healing Applications

7

Fig. 4 MTT assay of the electrospun nanofibrous bandage using NIH 3T3 cell lines, a Cell viability graph (i) PVP (ii) AgNps-Cur-PVP and b SEM image of NIH 3T3 cell lines seeded on AgNps-Cur-PVP bandage after 72 h

confirmed by antibacterial activity which shows good zone of inhibition. The excellent cell viability, non-toxic nature, good cell attachment and proliferation rate of the electrospun AgNps-Cur-PVP nanofibrous bandage were confirmed by MTT assay using NIH 3T3 cell lines. The proposed electrospun AgNps-Cur-PVP nanofibrous bandage for biomedical applications will be useful as a wound-covering patch to treat skin cancers or implanted inside the body to treat cancer cells. However, their applicability as curcumin and silver nanoparticles-incorporated nanofibrous bandage must be assessed by in vivo methods and studied further. Acknowledgements The authors gratefully acknowledge the instrumentation facility provided under UGC XI plan-2009–2010 for double-beam ultraviolet spectroscopy and UGC–Autonomy grant 2017–2018 for electrospinning apparatus to the Department of Chemistry, Sri Sarada College for Women (Autonomous), Salem–636016.

8

E. Thangaraju et al.

References 1. Khalil EA, Abou-Zekry SS, Sami DG, Abdellatif A (2021) Natural products as wound healing agents. In: Kumar P, Kothari V (eds) Wound healing research. Springer, Singapore 2. Goel A, Kunnumakkara AB, Aggarwal BB (2008) Curcumin as “Curecumin”: From kitchen to clinic. Biochem Pharmacol 75:787–809 3. Dhivya S, Vijaya Padma V, Santhini E (2015) Wound dressings—a review. Biomedicine 5:24– 28 4. Dong Y, Zheng Y, Zhang K, Yao Y, Wang L, Li X, Yu J, Ding B (2020) Electrospun nanofibrous materials for wound healing. Adv Fiber Mater 2:212–227 5. Norman JJ, Desai TA (2006) Methods for fabrication of nanoscale topography for tissue engineering scaffolds. Ann Biomed Eng 34:89–101 6. Ramakrishna S, Fujihara K, Teo WE, Lim TC, Ma Z (2005) An introduction to electrospinning and nanofibers. World Scientific Publishing, Singapore 7. Roso M, Boaretti C, Lorenzetti A, Modesti M (2015) Electrospun nanofibrous membranes. Encyclopedia of Membranes. Springer, Heidelberg 8. Jian F, HaiTao N, Tong L, XunGai W (2008) Applications of electrospun nanofibers. Chin Sci Bull 53:2265–2286 9. Zahedi P, Rezaeian I, Ranaei-Siadat S, Jafari S, Supaphol P (2010) A review on wound dressings with an emphasis on electrospun nanofibrous polymeric bandages. Polym Adv Technol 21:77– 95 10. Kokabi M, Sirousazar M, Muhammad Hassan Z (2007) PVA-clay nanocomposite hydrogels for wound dressing. Eur Polymer J 43:773–781 11. Fogaca R, Catalani LH (2013) PVP hydrogel membranes produced by electrospinning for protein release devices. Soft Mater 11:61–68 12. Folttmann H, Quadir A (2008) Polyvinylpyrrolidone (PVP)—one of the most widely used excipients in pharmaceuticals: an overview. Drug Deliv Technol 8:22–27 13. Dai XY, Nie W, Wang YC, Shen Y, Li Y, Gan SJ (2012) Electrospun emodin polyvinylpyrrolidone blended nanofibrous membrane: a novel medicated biomaterial for drug delivery and accelerated wound healing. J Mater Sci Mater Med 23:2709–2716 14. Liu X, Xu Y, Wu Z, Chen H (2013) Poly (N-vinyl pyrrolidone)-modified surfaces for biomedical applications. Macromol Biosci 13:147–154 15. Franco P, De Marco I (2020) The use of poly (N-vinyl pyrrolidone) in the delivery of drugs: a review. Polymers 12:1114 16. Semnani D, Poursharifi N, Banitaba N, Fakhrali A (2018) Electrospun polyvinylidene pyrolidone/gelatin membrane impregnated with silver sulfadiazine as wound dressing for burn treatment. Bull Mater Sci 41:72 17. Roy N, Saha N, Kitano T, Saha P (2010) Development and characterization of novel medicated hydrogels for wound dressing. Soft Mater 8:130–148 18. Alven S, Nqoro X, Aderibigbe BA (2020) Polymer-based materials loaded with curcumin for wound healing applications. Polymer 12:2286 19. Sridhar R, Sundarrajan S, Ravichandran VJR, R, Ramakrishna S, (2013) Electrospun inorganic and polymer composite nanofibers for biomedical applications. J Biomater Sci—Polym Edn 24:365–385 20. Salami MS, Bahrami G, Arkan E, Izadi Z, Miraghaee S, Samadian H (2021) Co-electrospun nanofibrous mats loaded with bitter gourd (Momordicacharantia) extract as the wound dressing materials: in vitro and in vivo study. BMC Complement Med Ther 1:111 21. Samadian H, Zamiri S, Ehterami A, Farzamfar S, Vaez A, Khastar H, Alam M, Ai A, Derakhshankhah H, Allahyari Z, Goodarzi A, Salehi M (2020) Electrospun cellulose acetate/gelatin nanofibrous wound dressing containing berberine for diabetic foot ulcer healing: in vitro and in vivo studies. Sci Rep 10:8312 22. Jayakumar R, Prabaharan M, Shalumon KT, Chennazhi KP, Nair SV (2011) Biomedical applications of polymeric nanofibers. In: Jayakumar R, Nair S (eds) Biomedical applications of polymeric nanofibers. Advances in polymer science, vol 246. Springer, Heidelberg

Biopolymeric Nanofibrous Bandage for Wound-Healing Applications

9

23. Zhang H, Peng M, Cheng T, Zhao P, Lipeng Q, Zhou J, Lu G, Chen J (2008) Silver nanoparticles—doped collagen-alginate antimicrobial biocomposite as potential wound dressing. J Mater Sci 53:14944–14952 24. Augustine R, Hasan A, Yadu Nath VK, Thomas J, Augustine A, Kalarikkal N, Al Moustafa AE, Thomas S (2018) Electrospun polyvinyl alcohol membranes incorporated with green synthesized silver nanoparticles for wound dressing application. J Mater Sci Mater Med 29:163 25. Sharma A, Khanna S, Kaur G, Singh I (2021) Medicinal plants and their components for wound healing applications. Future J Pharmaceutical Sci 7:53 26. Priyadarsini KI, Maity DK, Naik GH, Kumar MS, Unnikrishnan MK, Satav JG, Mohan H (2003) Role of phenolic O-H and methylene hydrogen on the free radical reaction and antioxidant activity of curcumin. Free Radical Biol Med 35:475–484 27. Thangapazham RL, Sharma A, Maheswari RK (2007) Beneficial role of curcumin in skin diseases. In: Aggarwal BB, Surh YJ, Shishodia S (eds) The molecular targets and therapeutic uses of curcumin in health and disease. Advances in experimental medicine and biology, vol 595. Springer, Boston 28. Pritarighat S, Ghannadnia M, Baghshahi S (2019) Green synthesis of silver nanoparticles using the plant extract of Salvia spinosa grown in vitro and their antibacterial activity assessment. J Nanostruct Chem 9:1–9 29. Hettiarachchi SS, Dunuweera SP, Dunuweera AN, Gamini RM, Rajapakse (2021) Synthesis of curcumin nanoparticles from raw turmeric rhizome. ACS Omega 6:8246–8252 30. Thangaraju E, Srinivasan NT, Kumar R, Sehgal PK, Rajiv S (2012) Fabrication of electrospun poly (L-lactide) and curcumin loaded poly (L-lactide) nanofibers for drug delivery. Fibers Polym 13:823–830 31. Thilakam R, Elakkiya T, Vidhyadevi G (2018) Organic compound incorporated Poly (vinyl alcohol) nanofibrous scaffold for tissue engineering applications. IAETSD J Adv Res Appl Sci 5:270–288 32. Mosmann T (1983) Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. J Immunol Methods 65:55–63 33. Anandalakshmi K, Venugobal J, Ramasamy V (2016) Characterization of silver nanoparticles by green synthesis method using Pedalium murex leaf extract and their antibacterial activity. Appl Nanosci 6:399–408 34. He Y, Liu H, Bian W, Liu Y, Liu X, Ma S, Zheng X, Du Z, Zhang K, Ouyang D (2019) Molecular Interactions for the curcumin-polymer complex with enhanced anti-inflammatory effects. Pharmaceutics 11:442 35. Barczikai D, Kacsari V, Domokos J, Szabo D, Jedlovszky-Hajdu A (2021) Interaction of silver nanoparticle and commonly used anti-inflammatory drug within a poly(amino acid) derivative fibrous mesh. J Mol Liquids 322:114575

Preparation and Characterization of Polymer Biocomposite 3D Mat for Bone Tissue Regeneration Gurumoorthi Ramar, Bhuvana K. Periyasamy, R. Joseph Bensingh, and S. K. Nayak

1 Introduction Bone is a complex organ and forms the skeletal plasticity structure of gravity, which has a three-dimensional porous structures. Large bone defect needs only surgery to repair the bone because the recovery process is beyond the capability of selfrepair of the human bone. The autograft method is the golden standard for bone treatment, but it has lot of limitations such as graft resorption, donor site morbidity and hemorrhage [1]. Bone tissue engineering is a great replacement for the autogenous bone grafts where the grafts are made using the natural and synthetic substitutes to restore the bone defects. The bone scaffold should be biodegradable, non-toxic, biocompatible, having desired mechanical properties, transport the nutrients (oxygen, growth factors and waste) and mimic the composition and structure of the bone [2]. Time-consuming, high cost and manufacturing difficulty limited the benefits of clinical outcome, and translational hurdles were some of the problems to replicate the fracture bone using bone implants. So, the major challenge in the bone regeneration is to have a suitable method with minimal materials to achieve the clinical success. Electrospinning is a popular, simple method and versatile way to fabricate both, micro- and nanoscale fibers for tissue engineering application. Electrospinning formed the high surface-to-volume ratio and unique fibers with interconnected porous structure mimicking the morphological shape of the extracellular matrix (ECM) for bone tissue engineering. The ECM interacts with cell and gives structural, functional and mechanical support [1]. The electrospinning method enticing the nanoparticles G. Ramar (B) · B. K. Periyasamy · S. K. Nayak Department of Petrochemical Technology, Central Institute of Petrochemical Engineering and Technology (CIPET), Chennai, India B. K. Periyasamy e-mail: [email protected] R. Joseph Bensingh · S. K. Nayak CIPET: School for Advanced Research in Polymers (SARP)—APDDRL, Bengaluru, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_2

11

12

G. Ramar et al.

incorporated into the polymer to form nanofiber is the most predominant feature in the bone regeneration. The human bone is composed of 35% of organic (proteins), 25% of water and 40% of inorganic materials (calcium phosphate). Commonly used synthetic bone substitute for calcium phosphate is derived from hydroxyapatite and tricalcium phosphate. Calcium phosphate shows good osteoconductive properties but has either slow resorption (inhibit osteointegration) or fast resorption (insufficient filling) [3]. Bioactive glass (BG) is a popoular alternative for calcium phosphate, and it is a form of carbonate-substituted hydroxyapatite layer on the surface. BG is osteostimulative in nature [4]. Bioglass materials are mineralized both intracellular and extracellular at the interface because ions are released from the surface and form mature bone structures. The sol–gel method leads to the advantageous properties of BG like low processing temperature, higher porosity, apatite-forming ability, modification of surface composition and homogenous nanostructures with high surface area. The different compositions of BG for various biological applications are 45S5 (osteoblast), 58S (biomaterial coating), 6P53-b (bone defect filling), MBG85 (fibroblast), BG60S (increase Ca2+ signals), A/W bioactive glass ceramic (promote bone regeneration), cervital glass ceramic (osteoactive material), 5554.3 bioactive glass (soft tissue regeneration), S53P4 (bone cavity filling), etc. Among them, 45S5 bioglass has higher index of bioactivity (IB) and develops better ability to attach with both hard and soft tissues in comparison with other bioglasses [5]. The 45S5 bioglass mimics the function and structure of the ECM of the bone. Doping agent interacts with the fibroblast growth factor (FBG), vascular endothelial growth factor (VEGF), bone morphogenetic protein-2 (BMP2) and releases them in different time interval to form the angiogenesis [6]. But, 45S5 bioglass has no flexibility nor machinability properties to be efficiently and easily used for bone application. Hence, it is combined with polycaprolactone (PCL) which is bioresorbable and tissue compatible for clinical applications. FDA has approved PCL for its biocompatible and biodegradable properties. Electrospun PCL scaffold nanofibers are tested for their biocompatible, osteoconductive and osteoinductive properties in in vitro and in vivo conditions. PCL polymer provides high rheological, viscoelastic properties and slow degradation rate (hydrophobic behavior) [7]. PCL/BG matrix has improved the mechanical properties, tunable degradation rates, bioactivity and enhancement in the hydrophilicity and cell interactions [8]. Nanostructured material shows an effective properties than the bulk material due to large surface-to-volume ratio. Electrospun fibrous scaffolds form high porosity with interconnected network for bone regeneration. Here, we reported the effect of 45S5 bioactive glass nanoparticles on the physiochemical properties of PCL/45S5 bioactive glass 3D mat scaffold. Optimization of the prepared composite scaffold was performed, and biodegradation kinetics, bioactivity and swelling studies were done.

Preparation and Characterization of Polymer Biocomposite …

13

2 Materials and Methods 2.1 Synthesis of Bioglass The composition of the 45S5 bioactive glass is SiO2 45%, NaO 24.5%, P2 O5 6% and CaO 24.5% in molar percentage, and the composition was chosen based on the ternary phase diagram [5]. Sol–gel method is a bottom-up approach (colloidal suspension) for synthesis of nanomaterials at low temperature. To acid hydrolyze TEOS, 3.11 mL of tetraethyl orthosilicate and 6.22 mL of ethanol were stirred for 30 min. Distilled water was added to the above solution in the ratio of 2:1. After 30 min, sodium nitrate solution (1.24 g of sodium nitrate dissolved in 1.24 mL of nitric acid) was added dropwise into the reaction mixture. After time interval of 30 min, calcium nitrate tetrahydrate solution (1.91 g calcium nitrate tetrahydrate dissolved in 3.82 mL of water) was added to the above reaction mixture. Subsequently, a solution containing 0.1352 mL of P2 O5 in 0.27 mL of ethanol was added. The whole of the reaction mixture was stirred continuously for 4 h. Then, the solution was sealed and incubated for two weeks at room temperature for the gelation to occur through hydrolysis and polycondensation reactions. The obtained gel was dried at 120 °C for 48 h in hot air oven. The dried powder was calcined for nitrate elimination and stabilization of the gel. The calcination temperature was determined by TGA analysis which is as explained in Sect. 3.1.

2.2 Synthesis of Biocomposite Electrospun Scaffold Polycaprolactone (PCL, MW = 80,000 g/mol; Sigma-Aldrich) (8% w/v) solution was prepared by dissolving PCL pellets in chloroform: ethanol (Sigma-Aldrich) (9:1) mixture. Biocomposite was prepared by adding 45S5 bioactive glass to PCL solution. The clear composite solution obtained after stirring 2 h was electrospun using electrospinning setup consisting of a DC high power supply, dual polarity, syringe pump, syringe (dispovan) and a needle (24G) with a blunted tip. The DC highvoltage positive terminal was connected to the syringe, whereas the negative terminal was connected to the metallic plate. The PCL and PCL-BG fibers were obtained at an operating voltage of +12 and +15 kV, respectively. Electrospun fibers produced with 0.5 ml/hour flowrate were collected in aluminum foil kept over the metallic collector disk. During this process, the tip to collector distance was maintained as 12 cm.

14

G. Ramar et al.

2.3 Characterization Methods 2.3.1

Thermogravimetric Analysis (TGA)

The sintering behavior was verified in the bioactive glass using the thermogravimetric analysis (TGA instruments). The bioactive glass powder is heated from 27 °C temperature to 900 °C at the heating rate of 10 °C/min. This analysis can be carried out in the powder sample as per ASTM (E1131:2014).

2.3.2

X-ray Diffraction Studies

. The composite scaffold phase content was characterized by the X-ray diffraction analysis (XRD). The analysis was performed with fully automated X-ray diffractometer (Rigaku, MiniFlex, USA). The diffraction patterns were recorded using CuKα radiation (λ = 1.542 Å) at 35 kV and 40 mA. The sample was scanned in the interval of 1° < 28 < 80° at a scan speed of 10°/min in a continuous mode. Different phases in the sample have been identified by using JCPDS data files in PCPDFWIN software.

2.3.3

Fourier Transform Infrared Spectroscopy

The chemical moieties present in the composite scaffold were analyzed using Fourier transform infrared (FTIR) spectroscopy (thermoscientific). The absorption spectra were measured using an IR spectrometer in attenuated total reflection (ATR) condition at wave number ranging from 4000 to 500 cm−1 .

2.3.4

Scanning Electron Microscopy

The elemental composition of the composite scaffold was studied using energy dispersion X-ray (EDX) analysis. The microstructure and morphology of the electrospun scaffolds have been obseed under scanning electron microscopy (SEM) (model S-3000H Hitachi). The surface of the electrospun scaffolds was coated with a thin layer of gold (Au) and visualized under SEM at vacuum pressure.

2.3.5

Swelling and Degradation Study

Swelling and degradation studies were performed in simulated body fluid (SBF) solution. For swelling study, the composite scaffolds were immersed in the SBF solution incubated at 37 °C. At regular interval (0, 30, 60, 120…0.1440 min) of time, the swollen ratio was measured after removing the excess water present at the surface of the scaffold [9].

Preparation and Characterization of Polymer Biocomposite …

15

Swelling ratio {Weight of swollen scaffold (Ws) − Weight of dry scaffold(Wd)} × 100 = Weight of dry scaffold (Wd) For degradation study, the electrospun fiber scaffold was immersed in the SBF solution and incubated at 37 °C. At predetermined intervals (1, 3, 5, 7…28 days), the fiber was taken out of the solution and weighed after being completely dried. The experiments were conducted in triplets, and the mean data have been provided [10]. The degradation rate of the sample was calculated using the following formula: Weight loss =

2.3.6

{Initial weight of the sample (Wi) − Weight of the sample of the degradation in BF at interval (Wt)} × 100 Initial weight of the sample (Wi)

In Vitro Formation of an Apatite Phase

. The bioactive behavior of the PCL/BG nanofiber was assessed in terms of its apatiteforming ability by immersion test in Kokubo’s simulated body fluid (SBF). The PCL/BG nanofiber (2 cm × 2 cm) is immersed in the SBF solution and placed into the incubator at 37 ° C. The scaffold was taken at a particular time interval (7 days, 14 days…28 days) which was dried and stored for analysis. The formation of the hydroxycarbonate apatite (HCA) layer was evaluated using FTIR spectroscopy.

3 Results and discussion 3.1 Thermal Analysis In thermogravimetric analysis, the change in mass of dry powder which changes in temperature from 27–900 °C was measured and displayed in Fig. 1. The dry powder had a total weight loss of 56.197% in two stages. The first stage was attributed to the removal of water at around 119.63 °C (13.85%), whereas the second stage was attributed to the decomposition of NO3− groups at 517.35°C (21.88%). The sintering behavior of the dry powder synthesized was determined at 700 °C, where water and nitrate groups were removed completely. These results were similar to the values reported by Chitra et al. [11].

16

G. Ramar et al.

Fig. 1 Thermogravimetric analysis of the 45S5 bioactive glass sample

3.2 XRD Analysis X-ray diffraction studies were used to reveal the purity level of bioglass. The XRD pattern of bioactive glass is as shown in Fig. 2. The characteristic peaks of the bioglass are observed at 26.8°, 32.8°, 44.24°, 47.98°, 49.24° and 60.84° corresponding to (002), (211), (310), (222), (213) and (322) planes, respectively. The XRD peak matched with the standard bioglass pattern (JCPDS 78-1650) [12]. Combeite (Na2 Ca2 Si3 O9 ) has been the most significant phase which induces bioactivity.

The crystalline size was determined by Williamson-Hall plot (W–H plot) using the uniform deformation model (UDM). The UDM equation represents a linear equation (βhkl cos θ = (K λ/D) + (4ε sin θ ))

Preparation and Characterization of Polymer Biocomposite …

17

Fig. 2 The FTIR spectrum of the PCL-bioactive glass sample

with size factor (Kλ/D) and strain (ε). The crystallite size was estimated to be 6.2 nm. The % crystallinity was identified using the equation %crystallinity =

area of crystalline peak × 100% Total area

The % crystallinity was estimated as 16.37%. The diffraction peak, low crystallite size and % crystallinity denote the amorphous nature of the 45S5 bioactive glass.

3.3 FTIR Analysis FTIR analysis was used to identify the functional group in the PCL-bioglass nanofiber. The broadband at 3453 cm−1 corresponds to OH group. The dip at 2942 cm−1 was attributed to CH2 group, 1720 cm−1 and 1365 cm−1 correspond to C=O and C–O and C–C stretching group, and 1191 cm−1 was ascribed to the stretching vibration of Si–O–Si group. The band at 1042, 960, 731, 583 cm−1 was attributed to PO3− 4 groups of bioactive glass. Marina et al. observed similar spectrum of prepared bioglass in the FTIR analysis.

3.4 Morphology Analysis The morphology of PCL and PCL-BG nanofibrous mat that was prepared in the concentration of 8 and 8:1 (wt%) was observed through SEM analysis. The SEM micrographs of PCL and PCL-BG were shown in Fig. 3a and b, respectively,

18

G. Ramar et al.

Fig. 3 SEM microphotographs of a Electrospun PCL and b Electrospun PCL-bioglass nanofiber

which displayed uniform and randomly oriented nanofibers. No bead formation was witnessed in the fibrous mats which indicated a smooth surface. The average diameter of PCL and PCL-BG was approximately 290 ± 40 nm and 116 ± 40 nm, respectively. The reason behind the difference in PCL and PCL-BG nanofiber diameter was that PCL-BG nanofibers were obtained at higher voltage compared to PCL nanofibers.

3.5 Biodegradation Study Ideal scaffold material should possess bioresorbable and biodegradable properties coinciding with the rate of new bone tissue formation. Hence, the steady and controlled degradation of scaffold material plays an important role in the new bone tissue regeneration. In vitro degradation studies of PCL and PCL-BG scaffold in SBF solution were conducted at 37 °C. The results showed that PCL has a low degradation rate than the PCL-BG scaffold. The PCL-BG scaffold had a steep weight loss of about 60% at the end of the 7th day. Later, the degradation rate attained a plateau where a maximum of 75% weight loss was observed at the end of 28th day. The higher degradation rate of the PCL-BG composite scaffold might be attributed to the incorporation of BG into PCL. The bioglass interacted via the hydrogen and ionic interaction with water molecules which weakened the interaction of PCL macromolecule and water. Similarly, the increase in the degradation rate of scaffolds was observed with incorporation of nanoparticles into the polymers in the earlier reports [6, 13].

Preparation and Characterization of Polymer Biocomposite …

19

Fig. 4 Swelling studies of the samples performed in SBF solution at 37 °C. The experiments were performed in triplicate, and the mean data have been provided

3.6 Swelling Studies The swelling of the biocomposite scaffold allows the absorption of the body fluid which helps in the transport of the nutrients and metabolites inside the scaffold. Swelling increases the total porosity, pore size and increases the internal surface area of the scaffold favorable for cell attachment and infusion. Physiological swelling conditions should be controlled; otherwise, it would result in the rapid degradation of the scaffold. Figure 4 denotes the swelling of PCL and PCL-BG with respect to time. The swelling of the PCL and PCL-BG scaffold increased sharply and reached saturation after an hour in the SBF solution at 37 °C. The degree of swelling rate decreased with the incorporation of bioglass content in the scaffold where the bioglass interacts with the cationic sites of inorganic phase and the carboxylic group in the PCL giving them higher elasticity. Hence, the composite scaffolds with higher elasticity resulted from the improved PCL-45S5 bioactive glass interactions display slower swelling ratio in comparison with PCL scaffold. A similar trend was reported several times in swelling study where the incorporation of nanoparticles into polymers decreased swelling rate of the composite in comparison with the polymer scaffolds [9, 10].

3.7 Bioactive Behavior The osteoconductive potential of the PCL-BG scaffold was assessed through in vitro biomineralization studies. The formation of the apatite phase in the PCL-BG scaffold immersed in the SBF solution was analyzed through FTIR which is as given in Fig. 5. The electrospun fiber was immersed in the SBF solution at 37 °C to mimic the body conditions. After one week of incubation, the apatite formation was analyzed.

20

G. Ramar et al.

Fig. 5 FTIR spectra of PCL/BG after 7 days of immersion in SBF for different times

The band was observed at 1013.86 cm−1 in the FTIR spectrum of the sample corresponding to the phosphate group (P–O bends) from the apatite deposition. The intensity of the band was observed to increase with time which indicated the formation of apatite on the surface of scaffold. The increased bioactivity of the composite scaffold is due to the incorporation of bioglass [14–16].

4 Conclusion In summary, bioactive glass and PCL fibrous scaffolds have been successfully prepared through electrospinning method. The average scaffold diameter of PCLBG was around 116 ± 40 nm. The bioactive glass (BG) was uniformly distributed throughout the PCL which enhanced the elasticity and mechanical property of the

Preparation and Characterization of Polymer Biocomposite …

21

composite. The biocomposite scaffold had a good swelling and degradation properties. The results showed a dense layer of apatite formation in the scaffold soaked in the SBF solution. Therefore, PCL-BG scaffold could serve as an artificial bone substitute in the bone tissue engineering. Acknowledgements The authors are thankful to the Department of Science and Technology (DST) Science of Equity Empowerment and Development (SEED), CIPET:IPT, Chennai, and Material Development Lab, CIPET:SARP-ARSTPS, Chennai, for providing the necessary supports to carry out above research work. Conflict of Interest The authors declare that there is no conflict of interests regarding the publication of this paper.

References 1. Li H, Huang C, Jin X, Ke Q (2018) An electrospun poly(ε-caprolactone) nanocomposite fibrous mat with a high content of hydroxyapatite to promote cell infiltration. RSC Adv 8(44):25228– 25235. https://doi.org/10.1039/C8RA02059K 2. Yu Y, Yang M, Hua S, Fu Z, Teng S, Niu K, Zhao Q, Yi C (2016) Fabrication and characterization of electrospinning/3D printing bone tissue engineering scaffold. RSC Adv 6(112):110557– 110565. https://doi.org/10.1039/C6RA17718B 3. Wang Q, Xu J, Jin H, Zheng W, Zhang X, Huang Y, Qian Z (2017) Artificial periosteum in bone defect repair—a review. Chinese Chem Lett 28(9):1801–180710. https://doi.org/10.1016/ j.cclet.2017.07.011 4. Fiume E, Barberi J, Verné E, Baino F (2018) Bioactive glasses: from parent 45S5 composition to scaffold-assisted tissue-healing therapies. J Funct Biomater 9(1).https://doi.org/10.3390/jfb 9010024 5. Hench LL (1998) Biomaterials: a forecast for the future. Biomaterials 19(16):1419–1423. https://doi.org/10.1016/s0142-9612(98)00133-1 6. Petretta M, Gambardella A, Boi M, Berni M, Cavallo C, Marchiori G (2021) Composite scaffolds for bone tissue regeneration based on pcl and mg-containing bioactive glasses. Biology (Basel) 10(5):1–18. https://doi.org/10.3390/biology10050398 7. Kolan K, Li W, Day DE, Ming CL (2016) 3D printing of a polymer bioactive glass composite for bone repair. In: Solid freeform fabrication 2016 proceeding 27th annual international solid freeform fabrication symposium—an additive manufacturing conference SFF 2016, no. January, pp 1718–1731 8. Fathi A, Kermani F, Behnamghader A, Banijamali S, Mozafari M, Baino F, Kargozar S (2021) Three-dimensionally printed polycaprolactone/multicomponent bioactive glass scaffolds for potential application in bone tissue engineering. Biomed Glas 6(1):57–69. https://doi.org/10. 1515/bglass-2020-0006 9. Asmaa MAEA, Ahemed AEF, Azza EM, Doaa AG, Kandil S (2021) Viscoelasticity, mechanical properties, and in vitro bioactivity of gelatin/borosilicate bioactive glass nanocomposite hydrogels as potential scaffolds for bone regeneration. Polymers (Basel) 13(12):2014. https:// doi.org/10.3390/polym13122014 10. Soni R, Vijay KN, Chameettachal S, Pati F, Rath SN (2019) Synthesis and optimization of PCLbioactive glass composite scaffold for bone tissue engineering. Mater Today Proc 15:294–299 11. Shivalingam C, Purushothaman B, Subramanian B (2020) Effect of microwave and probe sonication processes on sol–gel-derived bioactive glass and its structural and biocompatible investigations. J Biomed Mater Res Part B Appl Biomater 108(1):143–155. https://doi.org/10. 1002/jbm.b.34373

22

G. Ramar et al.

12. Hong W, Guo F, Hu L, Wang X, Xing C, Tan Y, Zhao X, Xiao P (2019) A hierarchically porous bioactive glass-ceramic microsphere with enhanced bioactivity for bone tissue engineering. Ceram Int 45(10):13579–13583. https://doi.org/10.1016/j.ceramint.2019.03.241 13. Henrique LT, Gabriella MFC, Carlos EDMJ, Rodrigo LO, Armando da SCJ, Min Zhao, Francine BC and Gisele RDS (2016) Bioactive glass nanoparticles-loaded poly(-caprolactone) nanofiber as substrate for ARPE-19 cells. J Nanomater 2016. https://doi.org/10.1155/2016/436 0659 14. Bargavi P, Shivalingam C, Purushothaman B, Subramanian B (2020) Bioactive, degradable and multi-functional three-dimensional membranous scaffolds of bioglass and alginate composites for tissue regenerative applications. Biomater Sci 8(14):4003–4025. https://doi.org/10.1039/ d0bm00714e 15. Shahin-SA AH, Tahriri M, Bastami F, Salehi M, Mashhadi AF (2018) Mechanical, material, and biological study of a PCL/bioactive glass bone scaffold: Importance of viscoelasticity. Mater Sci Eng C 90(April):280–288. https://doi.org/10.1016/j.msec.2018.04.080 16. Izabella Rajzer MD, Kurowska A, Katarzyna CK, Ziabka M, Menszek E, Timothy ELD (2019) Electrospun polycaprolactone membranes with Zn-doped bioglass for nasal tissues treatment. J Mater Sci Mater Med 30(7). https://doi.org/10.1007/s10856-019-6280-4

Growth and Spectral Features of Silver-Doped Aniline–Formaldehyde Nanocomposite Polymer: Density Functional Theory Investigation Anant D. Kulkarni, Giriraj Tailor, and Libero J. Bartolotti

1 Introduction Nanocomposite, a matrix of nanoparticles arranged in a way to enhance the properties of materials, viz. mechanical strength, toughness and electrical or thermal conductivity, etc., has been the subject of several intense experimental and computational investigations. The polymer composite forms the most widely commercialized domain of nanocomposites with the global revenue of about US$16.66 Billion for 2020 with compound annual growth rate of 9.9% [1]. The reason for this tremendous growth may be attributed to their unique chemical and mechanical properties and the diversified applications in almost all branches of science and engineering. The prototype example of unique properties is polymer composite group of materials that are preferred over the conventional metallic materials in aerospace industry due to their light weight, specific strength properties, better three-dimensional stability, lower thermal expansion properties, excellent fatigue as well as fracture resistance [2–10]. Recent literature reveals several reviews, monographs and texts on nanocomposite materials that are dedicated to synthesis, characterization, modification and applications of polymer composite materials [2–10]. The following section presents a brief review of these studies of nanocomposite materials doped with and without silver.

A. D. Kulkarni (B) Department of Polymer Science, S. K. Somaiya College, Somaiya Vidyavihar University, Mumbai 400077, India e-mail: [email protected] G. Tailor Department of Polymer Science, Mohan Lal Sukhadia University, Udaipur 313001, India L. J. Bartolotti Department of Chemistry, East Carolina University, Greenville, NC 27858-4353, USA e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_3

23

24

A. D. Kulkarni et al.

Designing, methods and applications of nanocomposite materials were reviewed by Bogue [9]. This study also highlights the importance of carbon nanotube (CNT)based polymer nanocomposites owing to their unique mechanical and electrical properties such as Young’s modulus, tensile strength, ultimate elongation, specific strength, thermal conductivity and electrical conductivity current carrying capacity that exceeds those of best traditional materials have been an important domain of intense research, development and applications [9]. Another review by Camargo et al. [10] focuses on three types of polymer nanocomposite materials with reference to their synthesis, structure, properties and possible applications, namely claybased minerals, chrysotile and lignocellulosic-based fibers, etc. In a detailed review, Kalia and coworkers [3] have reviewed potentially important applications of polymer nanocomposite in biomedical and environmental sciences. The applications include biomedicine, magnetic resonance imaging (MRI), targeted drug delivery, diagnosis and therapy for cancer, telecommunication, information technology (IT), removal of toxic effluents and heavy metals to name a few. In a very detailed review, Karak [11] discussed the historical aspect, methods for synthesis of Ag-based nanomaterials and silver-based polymer nanocomposites (Ag-PNCs). The characterization as well as various properties with special reference to antimicrobial activity is discussed in details. It was concluded that these materials can have potential applications in catalysis and other domains of biology. Yet another review by Sadasivuni and coworkers discusses the synthesis, optimization, as well as biomedical and other applications of Ag nanoparticles and Ag-PNCs [12]. Silver-based polymer nanocomposite (AgPNC) materials show better antimicrobial activity as compared to the larger silver particles due to availability of larger surface area for interaction with microbial cells [13–15]. Also, Ag-PNC materials have been a preferred choice due to their high antimicrobial activity [16], as well as better processing ability in terms of hightemperate stability and low volatility [17] over the other metallic nanomaterials, viz. copper, zinc, titanium [18], magnesium, gold [19] and alginate [20]. Johnston and coworkers [21] employed nano-structured calcium silicate (NCS) to adsorb Ag+ ions from a solution. The potential application of the NCS-Ag complex as antimicrobial agent into food packing was highlighted by the remarkable antimicrobial activity at 10 mg kg−1 of silver level. There exists several notable studies dealing with the antimicrobial activity of AgNP/polymer nanocomposite with wide range of polymer such as poly(acrylamide) [15], PVA [22], PVP [23], PMMA [24], PU [25], silicone elastomer [26], cellulose [27]. Chitosan, a polysaccharide possessing natural antimicrobial properties, is often incorporated into polymer nanocomposites to attain high level of antimicrobial effect [28–35]. Also, chitosan-based silver nanopolymer (AgNP) films show improved strength, mechanical properties and gas barrier properties than virgin films of the individual material [36, 37]. The synthesis and the estimation of antibacterial activity of chitosan-silver oxide nanocomposite film against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus has been reported by Tripathi and coworkers [38]. On the basis of their novel study, they advocated the advantage of using nanocomposite film or coating the food with provide protection from microbial growth as well as extend the shelf life.

Growth and Spectral Features of Silver-Doped Aniline …

25

Kale, Kulkarni and coworkers [39–41] performed series of detailed studies on synthesis, spectroscopic characterization and applications of silver-polyaniline nanocomposite (Ag-PANC) materials. The authors also investigated the anti-quorum sensing activity of silver-polyaniline nanowires synthesized. It was observed that the nanowire provides mediated inhibition of biofilm present in P. aeruginosa. This activity is a signature of therapeutic applications of Ag-PANC against pathogens that are resistant towards many antibiotics. Ivanova et al. [42] explored the structurephase changes and electrocatalytic activity of silver nanocomposite through X-ray phase analysis as well as electron microscopic analysis. Through their analysis, they demonstrated the relationship between the photocatalytic activity and the structure of the polymer matrix. Zhou et al. [43] assessed the performance of polyanilineencapsulated silicon on three-dimensional carbon nanotubes for anodic material in lithium-ion batteries (LIB). Their polymer composite material shows improvement over the other materials that are being employed for anode in LIBs. A recent experiments dealing with a strategy for improving the specific capacitance of the Ag-PANI electrode [44] also exist in the literature. Due to very high electrical and thermal conductivities, silver nanocomposite forms an important class of metal nanomaterials. The diversified potential applications of silver nanomaterials include catalysis, conductive inks, formulation of thick film pastes as well as adhesives for a wide range of electronic components and applications in photonics and photography industry [45–48]. The methods to synthesize include photoreduction, [48] ultrasonic irradiation [49], as well as the microwave irradiation. Hoque et al. [50] synthesized a dual-function polymer-silver nanocomposites based on a polymer with biodegradable ability and antimicrobial activity. The dielectric properties of poly(vinylidene fluoride) (PVDF)-based composites doped with nanosilver (Ag) deposited nickelate were explored by Meeporn and Thongbai [51]. The resulting composites show low dielectric loss (tan δ) of 0.027 at specific frequency region as well as high dielectric permittivity (ε ), 62. It was proposed that due to the good mechanical flexibility and greater dielectric properties, AgMLSNO/PVDF composites can be used in high-technology future applications. Improved energy density and thermal conductivity of silver nanoparticle-modified alumina microsphere hybrid composites were studied by Ren et al. [52]. According to this study, these polymer composite epoxy resins and silver nanoparticles decorated Al2 O3 nanoparticles have enhanced energy storage density and better thermal conductivity. The dielectric loss of pure epoxy resins as well as Al2 O3 -epoxy composites show linear dependence on its frequency. It was concluded that the prevention of silver nanoparticles in connecting to conducting pathways could be employed to obtain the polymer composites with high dielectric loss and breakdown strengths. Thus, it may be seen from the above discussion that the polymer nanocomposites, in particular Ag-based polymer nanocomposite materials, are a domain of intense research. The present investigation embarks on the reaffirmation of the experimentally estimated vibrational IR spectral analysis, as well as nuclear magnetic resonance (NMR) spectra by simulating their counterparts with the density functional theory (DFT) framework. The present investigation is also focused on predicting the growth

26

A. D. Kulkarni et al.

of the polymer of Ag-nanocomposite employing the guidelines proffered by molecular electrostatic potential (MESP) features of the monomer, dimer and trimer of the composite material.

2 Methodology 2.1 Experimental Details Synthesis of silver nanocomposite has been discussed by Chaudhary et al. [53]. Fourier transform infra-Red (FTIR) spectrum of the aniline–formaldehyde silver complex was recorded in the wavenumber range of 400–4000 cm−1 by preparing KBr pellet of the sample. Nuclear magnetic resonance 1 H (NMR) spectra was recorded with reference to tetramethyl silane (TMS). The details may be found elsewhere [53].

2.2 Computational Framework Density functional theory (DFT) has established itself as a powerful tool for the description of microscopic quantum systems such as atoms, molecules and solids in terms of the electron density for past several years [54–69]. A quick view at the recent literature reveals several studies that involves the application of DFT framework for diversified range of problems including polymer structure prediction, thermodynamics in bulk polymer systems, blends, polymer melts, polymer grafts, polymer-nanoparticle systems, phase transitions in polymers and so on [70–79]. Selection of an appropriate DFT-functional is the most crucial part while finalizing the computational framework for any computational problem. Minnesota density functionals are the meta-generalized gradient approximation (meta-GGA)based exchange-correlation energy functionals developed by Truhlar and coworkers [63–68, 80–84] employing strategies, empirical fits and mixing Hartree–Fock and approximate DFT exchange. Thus, these density functionals are highly parameterized using several benchmarking databases and have complicated functional form. The databases include highly accurate databases for structural parameters for noncovalent interactions, thermochemistry, kinetics, transition metal bonding, metal atom excitation energies and molecular excitation energies. Several studies and reviews [63–68, 80–96] discuss the broad applicability and reliability of Minnesota density functionals for diversified problems in for main group reactions and thermochemistry, kinetics, non-covalent interactions, organometallics, transition metal thermochemistry, as well as solid-state physics applications to name a few. Recently, Wu and Truhlar [80] performed a benchmarking investigation of accuracy of several density functionals with special reference to large molecular systems. They

Growth and Spectral Features of Silver-Doped Aniline …

27

concluded that several density functionals, viz. PW6B95-D4, PW6B95-D3(BJ), B97D3(BJ), revM11, M06-L, and MN15 yield accurate results when benchmarked with the results obtained employing highly correlated cluster-in-molecule domain-based local pair-natural-orbital coupled cluster method with single and double excitations and quasiperturbative connected triple excitations (CIM-DLPNO-CCSD(T)). Taking a cue from these investigations, we employ M06-2X functional along with triple zeta quality basis set, viz. def2-TZVP [97], for performing density functional theory (DFT) computations. The optimizations were followed by vibrational frequency and NMR calculations with Gaussian 09 [98] employing all default options. The integration grid used was “ultrafine” as defined in Gaussian 09. For NMR calculations, the modeled monomer was considered in the presence of the solvent dimethyl sulfoxide (DMSO) as modeled by IEFPCM-solvation framework [99–101]. Applications of scalar fields, viz. molecular electron density [102] and molecular electrostatic potential (MESP), [96, 102–118] to explore reactivity, structural features, molecular interactions, reactions, the growth of the clusters and crystals, reactions, excitation processes in solvated state is in practice for about five decades or so. Taking a cue from these studies, the electrostatic complementarity features of MESP were employed for predicting the structural growth of the monomer to dimer and trimer. The visualization of the structures and vibrational frequency analysis was done employing MeTA studio [119] package, a cross-platform, programmable integrated development environment (IDE) for computational chemists.

3 Results and Discussion Presented below are the results of computational investigation of vibrational IR and NMR spectra of Ag-formaldehyde-aniline nanocomposite resin with reference to the results from the experimental counterpart. The entire discussion pertains to M06-2X/def2-TZVP DFT model, unless stated otherwise. The details of synthesis and other experimental investigation may be found elsewhere [53]. This work may be thought as an extension of the experimental counterpart. However, the main objective of the present work is to employ the DFT framework to reaffirm the vibrational modes of analysis as well as to predict the directionality of the growth of the modeled monomer employing MESP-based approach. The schematic representation of the Ag-nanocomposite polymer and DFToptimized modeled monomer structure is depicted in Fig. 1a and b, respectively.

28

R1

A. D. Kulkarni et al.

NH

R1

+

Ag R1

NH

R1 n

(a) Ag-PANI Polymer

(b) Structure of modeled monomer

Fig. 1 a Structure of Ag-nanocomposite polymer. b Structure of the monomer unit optimized with M06-2X/def2-TZVP density functional theory framework. The color convention is: carbon: gray, hydrogen: white sticks, nitrogen: blue, silver: big white ball

3.1 Simulated Infrared Vibrational Spectrum The IR frequencies were computed for the modeled monomer unit employing M06-2X/def2-TZVP DFT framework. Table 1 represents the computed as well as the experimentally measured vibrational IR frequencies. The computed vibration frequencies are scaled by 0.984, a scaling factor as advised by Alecu and coworkers [91]. The corresponding simulated IR spectrum for scaled vibrational frequencies is depicted in Fig. 2. It may be seen from Table 1 that Ag–N bending was observed experimentally for the frequency range of 498–598 cm−1 . The computations within DFT framework predict this band between the frequency range of 487.2 and 634.0 cm−1 . The C–H out of plane bending for aromatic ring was observed for the range of 770–880 cm−1 whereas the computational counterpart predicts the range of 795.1–841.8 cm−1 . The vibrations due to C–N stretching were observed for 1329–1474 cm−1 , while the DFT predicted frequencies were in the similar range, viz. 1389–1507 cm−1 . It should be noted that the computationally predicted C–N stretching may be categorized in to two sets, viz. Set-I: 1407.6, 1476.5 cm−1 for C–N stretching mixed with dominant C–C stretching and Set-II: 1520.2, 1527.3 cm−1 for dominating C–N stretch mixed with C–C stretch. The ranges assigned for other vibrations, viz. C–C stretching, aliphatic C–H stretching and N–H stretching, match closely with the computationally predicted vibrations frequencies. It is felt worthwhile to mention that the DFT computations predict the vibrational frequencies for bending and stretching modes that were not observed during the present experimental investigation. The vibrational bands are predicted at 1004 and 1088 cm−1 for C–C stretch, 1134 cm−1 for C–H out of plane bending, 1147.5, 1157.0, 1195.3 cm−1 for C–C–H bending and 1371.8, 1391.5 cm−1 corresponding to C–H bending. The intensities for all these vibrational frequencies are in the range

Growth and Spectral Features of Silver-Doped Aniline …

29

Table 1 Comparison of experimentally measured polymer metal complex in KBr and computed Infrared (IR) frequencies of monomer within M06-2X/def2-TZVP framework Experimental frequencies (cm−1 )

Computed frequencies (cm−1 )

Mode assignment

498–598

480.8 (452.9), 529.1 (76.9), 568.7 (47.3), 625.6 (302.0)

Ag–N bend

770–880

784.6 (40.2), 830.7 (159.6)

C–H out of plane bending vibrations of aromatic ring

Not analyzed

1004.0 (25.6), 1088.7 (36.5)

C–C stretch

Not analyzed

1134.7 (253.4)

C–H out of plane bending

Not analyzed

1147.5 (42.4), 115.7 (276.2), 1195.3 (49.5)

C–C–H bending

Not analyzed

1353.7 (61.3), 1373.1 (222.9)

C–H bending

1329–1474

1389.0 (221.5), 1457.0 (938.8)

C–N stretch +C–C stretch (dom)a

1500.1 (41.14), 1507.1 (266.5)

C–N stretch (dom) +C–C stretch

1603–1706

1626.1 (250.9)

C–C stretch

2907–3010

3133.6 (36.9)

Aliphatic C–H stretching

3304

3437.3 (372.3), 3440.0 (80.1)

N–H stretching

Use scaling factor 0.971 for all the frequencies (dom)a Dominant mode

1200 1000

Intensity

Fig. 2 Simulated IR spectra of neutral monomer employing M06-2X/def2-TZVP DFT framework

800 600 400 200 0 400

1400

2400

3400

Wavelength (cm-1)

of 20–938 km/mol. We expect that these frequencies will be visible in the specialized IR techniques such as matrix isolation IR spectroscopy or so, where precise measurement of individual vibrational bands is possible.

30

A. D. Kulkarni et al.

3.2 Simulated NMR Spectrum The experimental NMR spectra for the Ag-PANI was recorded with reference to the DMSO structure. The geometry optimized structure of the monomer (Fig. 1b) was used for simulation of NMR spectra with the default options in Gaussian 09. The geometry optimization of the reference solvent molecule DMSO was employing the same DFT framework, viz. M06-2X/def2-TZVP. Figure 3 depicts experimentally recorded NMR. The experimental NMR shows the shielding peaks for three structure-specific proton groups, namely (i) 3.6 and 4.2 ppm corresponding to protons from methylene group, (ii) a set of two resonance peak at 5.3 and 8.8 ppm due to terminal amine group formed by the removal of one proton by silver ion in (Ag–NH bond) and (iii) 6.4–7.7 ppm corresponding to (aromatic) protons on phenyl ring. The simulated NMR also yield resonance peaks in three ranges. The simulated peaks for aromatic protons from amine show decent agreement with the experiment. Also, the simulated peak for protons of terminal amine group (at 7.02 ppm) shows very close agreement with the average value of two experimentally observed peaks, viz. 5.3 and 8.8 ppm (average = 7.05 ppm). Table 2 reports a comparison of experimentally measured NMR peaks as well as the simulated NMR peaks as discussed above. The third group of simulated peaks appears at slightly lower ppm values which is attributed to the fact that the simulated NMR corresponds to the modeled monomer Fig. 3 Experimental NMR of the nanocomposite material. Refer text for further details

Table 2 NMR shielding peaks (in ppm) for the actual Ag-doped polymer nanocomposite

NMR shielding peaks assignment

Experimental peaks

DFT simulation peaks

Protons of methylene

3.6, 4.2

1.98

Terminal amine group

5.3, 8.8

7.02

Aromatic protons of amine

6.4–7.7

5.9–6.7

Refer text for details

Growth and Spectral Features of Silver-Doped Aniline …

31

Fig. 4 MESP isosurface of value − 31.38 kcal mol−1 (depicted by blue solid surface) for M062X/def2-TZVP optimized structures of Ag-nanocomposite monomer. The color convention is: carbon: gray, hydrogen: white sticks, nitrogen: blue, silver: big white ball, chlorine (for charge compensation): sea green. Refer text for details

in which the monomer-linking methylene groups are replaced by terminal methyl groups. However, it should be noted that the simulated NMR spectra by far and large show a decent qualitative agreement with the experimentally observed counterpart.

3.3 MESP Predictions for Polymer Growth We explore MESP features of the monomer unit to predict the directionality for the polymer growth. MESP isosurface computed for the monomer unit is depicted in Fig. 4. It may be seen that the negative value MESP isosurface (shown by solid blue surface over the ball and stick model) of value − 31.38 kcal mol−1 is present on the lateral side of the monomer near the nitrogen atoms as well as near the Ag-atoms on the side opposite to benzene rings. This is an indication for the non-planar growth of the monomer in three dimensions. The approach is further extended to explore the structures of dimer and trimer of Ag-nanocomposite (Ag-ANIF). The schematic representation of the DFT-optimized structures of prototype dimer and trimer of modeled nanocomposite is depicted in Fig. 5a and b, respectively. Thus, the non-planar structures highlights the ability of MESP for predicting the directionality for the further growth of Ag-nanocomposite polymer.

4 Conclusions This article comprises the investigation of the structural growth and spectral features, viz. vibrational IR, NMR spectra of modeled Ag-formaldehyde-aniline

32

A. D. Kulkarni et al.

(a) Ag-ANIF dimer

(b) Ag-ANIF dimer trimer

Fig. 5 Structures of Ag-ANIF dimer a dimer and b trimer optimized employing M06-2X/def2TZVP framework. Carbon atoms are depicted in gray color, hydrogen atoms in white sticks and silver atom with big white sphere. Refer text for details

nanocomposite polymer within DFT framework. DFT computations were performed employing M06-2X density functional to rationalize the experimental results. The bands of simulated IR spectra show very good agreement with those obtained from the experiment. Also, the simulated NMR spectrum is in a decent agreement with the experimental NMR. The agreement of two spectra, viz. IR and NMR, indeed highlights the robustness and accuracy of DFT approach, in particular Minnesota density functionals, to investigate the structural and spectral features of polymeric systems right at molecular level. This is in agreement with the other notable studies [92, 110, 111]. MESP guidelines offer a simplified yet very important approach to predict the growth of the polymer [116]. It may be inferred that the MESP-based approach in conjugation with the cluster-building approach and molecular tailoring approach [120] can be gainfully employed to investigate larger polymeric systems within ab initio quantum chemical and DFT framework. It is expected that the present study should serve as a precursor for development of better model for studying polymer nanocomposite materials. Such studies on molecular, polymer and crystal systems are underway in our laboratory. Acknowledgements ADK thanks Prof. Shrikant V. Lonikar (P. A. H Solapur University, Solapur, India), Dr. Prakash P. Wadgaonkar, CSIR-NCL, Pune, India) and Dr. Milind V. Kulkarni (Centre for Materials and Electronics Technology (C-MET), Pune, India) for several stimulating discussions, suggestions and referencing during the course of this work. Notes The authors declare no competing financial interest.

Growth and Spectral Features of Silver-Doped Aniline …

33

References 1. Insights on the polymer matrix composites global market to 2026—cumulative impact of COVID-19 (2021). https://www.globenewswire.com/news-release/2021/08/25/2286140/ 28124/en/Insights-on-the-Polymer-Matrix-Composites-Global-Market-to-2026-Cumula tive-Impact-of-COVID-19.html. Accessed 15 Nov 2021 2. Mohanty S, Nayak SK, Kaith BS, Kalia S (2015) Polymer nanocomposites based on inorganic and organic nanomaterials. Wiley, New Jersey 3. Kalia S, Kango S, Kumar A, Haldorai Y, Kumari B, Kumar R (2014) Magnetic polymer nanocomposites for environmental and biomedical applications. Colloid Polym Sci 292(9):2025–2052. https://doi.org/10.1007/s00396-014-3357-y 4. Kalia S, Kaith BS, Kaur I (2009) Pretreatments of natural fibers and their application as reinforcing material in polymer composites—a review. Polym Eng Sci 49(7):1253–1272. https://doi.org/10.1002/pen.21328 5. Das M (2015) Nanocomposites in food packaging. In: Polymer nanocomposites based on inorganic and organic nanomaterials, pp 519–571. https://doi.org/10.1002/9781119179108. ch15 6. Mollo M, Bernal C (2015) Polymer nanocomposites for structural applications. In: Polymer nanocomposites based on inorganic and organic nanomaterials, pp 505–518. https://doi.org/ 10.1002/9781119179108.ch14 7. Jandas PJ, Mohanty S, Nayak SK (2015) Green nanocomposites from renewable resourcebased biodegradable polymers and environmentally-friendly blends. In: Polymer nanocomposites based on inorganic and organic nanomaterials, pp 401–442. https://doi.org/10.1002/ 9781119179108.ch11 8. Ghosh S, Chilaka N (2015) Polymer nanocomposites for energy storage applications. In: Polymer nanocomposites based on inorganic and organic nanomaterials, pp 483–503. https:// doi.org/10.1002/9781119179108.ch13 9. Bogue R (2011) Nanocomposites: a review of technology and applications. Assembly Autom 31(2):106–112. https://doi.org/10.1108/01445151111117683 10. Camargo PHC, Satyanarayana KG, Wypych F (2009) Nanocomposites: synthesis, structure, properties and new application opportunities. Mater Res 12:1–39 11. Karak N (2019) Silver nanomaterials and their polymer nanocomposites. In: Karak N (ed) Nanomaterials and polymer nanocomposites, Chap. 2. Elsevier, pp 47–89. https://doi.org/10. 1016/B978-0-12-814615-6.00002-3 12. Sadasivuni KK, Rattan S, Waseem S, Brahme SK, Kondawar SB, Ghosh S et al (2019) Silver nanoparticles and its polymer nanocomposites—synthesis, optimization, biomedical usage, and its various applications. In: Sadasivuni KK, Ponnamma D, Rajan M, Ahmed B, Al-Maadeed MASA (eds) Polymer nanocomposites in biomedical engineering. Springer International Publishing, Cham, pp 331–373. https://doi.org/10.1007/978-3-030-04741-2_11 13. Aymonier C, Schlotterbeck U, Antonietti L, Zacharias P, Thomann R, Tiller JC et al (2002) Hybrids of silver nanoparticles with amphiphilic hyperbranched macromolecules exhibiting antimicrobial properties. Chem Commun (24):3018–3019. https://doi.org/10.1039/B208575E 14. Sondi I, Salopek-Sondi B (2004) Silver nanoparticles as antimicrobial agent: a case study on E. coli as a model for gram-negative bacteria. J Colloid Interface Sci 275(1):177–182. https:// doi.org/10.1016/j.jcis.2004.02.012 15. Tankhiwale R, Bajpai SK (2009) Graft copolymerization onto cellulose-based filter paper and its further development as silver nanoparticles loaded antibacterial food-packaging material. Colloids Surfaces B Biointerfaces 69(2):164–168. https://doi.org/10.1016/j.colsurfb.2008. 11.004 16. Ahmad Z, Pandey R, Sharma S, Khuller GK (2006) Alginate nanoparticles as antituberculosis drug carriers: formulation development, pharmacokinetics and therapeutic potential. Indian J Chest Dis Allied Sci 48(3):171–176 17. Kumar R, Münstedt H (2005) Silver ion release from antimicrobial polyamide/silver composites. Biomaterials 26(14):2081–2088. https://doi.org/10.1016/j.biomaterials.2004.05.030

34

A. D. Kulkarni et al.

18. Schabes-Retchkiman PS, Canizal G, Herrera-Becerra R, Zorrilla C, Liu HB, Ascencio JA (2006) Biosynthesis and characterization of Ti/Ni bimetallic nanoparticles. Opt Mater 29(1):95–99. https://doi.org/10.1016/j.optmat.2006.03.014 19. Gu H, Ho P-L, Tsang KWT, Wang L, Xu B (2003) Using biofunctional magnetic nanoparticles to capture vancomycin-resistant enterococci and other gram-positive bacteria at ultralow concentration. J Am Chem Soc 125(51):15702–15703. https://doi.org/10.1021/ja0359310 20. Gong P, Li H, He X, Wang K, Hu J, Tan W et al (2007) Preparation and antibacterial activity of Fe3 O4 @Ag nanoparticles. Nanotechnology 18(28):285604. https://doi.org/10.1088/09574484/18/28/285604 21. Johnston JH, Borrmann T, Rankin D, Cairns M, Grindrod JE, McFarlane A (2008) Nanostructured composite calcium silicate and some novel applications. Curr Appl Phys 8(3– 4):504–507. https://doi.org/10.1016/j.cap.2007.10.060 22. Hong KH, Park JL, Sul IH, Youk JH, Kang TJ (2006) Preparation of antimicrobial poly(vinyl alcohol) nanofibers containing silver nanoparticles. J Polym Sci Part B Polym Phys 44(17):2468–2474. https://doi.org/10.1002/polb.20913 23. Zhang H, Wang X (2009) Fabrication and performances of microencapsulated phase change materials based on n-octadecane core and resorcinol-modified melamine–formaldehyde shell. Colloids Surfaces A Physicochem Eng Aspects 332(2):129–138. https://doi.org/10.1016/j.col surfa.2008.09.013 24. Kong H, Jang J (2008) Antibacterial properties of novel poly(methyl methacrylate) nanofiber containing silver nanoparticles. Langmuir 24(5):2051–2056. https://doi.org/10.1021/la7 03085e 25. Sheikh FA, Barakat NAM, Kanjwal MA, Chaudhari AA, Jung I-H, Lee JH et al (2009) Electrospun antimicrobial polyurethane nanofibers containing silver nanoparticles for biotechnological applications. Macromol Res 17(9):688–696. https://doi.org/10.1007/BF03218929 26. Furno F, Morley KS, Wong B, Sharp BL, Arnold PL, Howdle SM et al (2004) Silver nanoparticles and polymeric medical devices: a new approach to prevention of infection? J Antimicrob Chemother 54(6):1019–1024. https://doi.org/10.1093/jac/dkh478 27. Jung R, Kim Y, Kim H-S, Jin H-J (2009) Antimicrobial properties of hydrated cellulose membranes with silver nanoparticles. J Biomater Sci Polym Ed 20(3):311–324. https://doi. org/10.1163/156856209X412182 28. Akmaz S, Dilaver Adıgüzel E, Yasar M, Erguven O (2013) The effect of Ag content of the chitosan-silver nanoparticle composite material on the structure and antibacterial activity. Adv Mater Sci Eng 2013:690918. https://doi.org/10.1155/2013/690918 29. Fu J, Ji J, Fan D, Shen J (2006) Construction of antibacterial multilayer films containing nanosilver via layer-by-layer assembly of heparin and chitosan-silver ions complex. J Biomed Mater Res Part A 79A(3):665–674. https://doi.org/10.1002/jbm.a.30819 30. Thomas V, Yallapu MM, Sreedhar B, Bajpai SK (2009) Fabrication, characterization of chitosan/nanosilver film and its potential antibacterial application. J Biomater Sci Polym Ed 20(14):2129–2144. https://doi.org/10.1163/156856209X410102 31. Shukla SK, Mishra AK, Arotiba OA, Mamba BB (2013) Chitosan-based nanomaterials: a state-of-the-art review. Int J Biol Macromol 59:46–58. https://doi.org/10.1016/j.ijbiomac. 2013.04.043 32. Fernandez JG, Ingber DE (2014) Manufacturing of large-scale functional objects using biodegradable chitosan bioplastic. Macromol Mater Eng 299(8):932–938. https://doi.org/10. 1002/mame.201300426 33. Smith A, Perelman M, Hinchcliffe M (2014) Chitosan. Human Vaccines Immunotherapeutics 10(3):797–807. https://doi.org/10.4161/hv.27449 34. Xing Y, Lin H, Cao D, Xu Q, Han W, Wang R et al (2015) Effect of chitosan coating with cinnamon oil on the quality and physiological attributes of China Jujube fruits. BioMed Res Int 2015:835151. https://doi.org/10.1155/2015/835151 35. Ryu JH, Hong S, Lee H (2015) Bio-inspired adhesive catechol-conjugated chitosan for biomedical applications: a mini review. Acta Biomater 27:101–115. https://doi.org/10.1016/ j.actbio.2015.08.043

Growth and Spectral Features of Silver-Doped Aniline …

35

36. Yoksan R, Chirachanchai S (2010) Silver nanoparticle-loaded chitosan–starch based films: fabrication and evaluation of tensile, barrier and antimicrobial properties. Mater Sci Eng C 30(6):891–897. https://doi.org/10.1016/j.msec.2010.04.004 37. Podsiadlo P, Paternel S, Rouillard J-M, Zhang Z, Lee J, Lee J-W et al (2005) Layer-by-layer assembly of nacre-like nanostructured composites with antimicrobial properties. Langmuir 21(25):11915–11921. https://doi.org/10.1021/la051284+ 38. Tripathi S, Mehrotra GK, Dutta PK (2011) Chitosan–silver oxide nanocomposite film: preparation and antimicrobial activity. Bull Mater Sci 34(1):29–35. https://doi.org/10.1007/s12034011-0032-5 39. Wagh MS, Patil RH, Thombre DK, Kulkarni MV, Gade WN, Kale BB (2013) Evaluation of anti-quorum sensing activity of silver nanowires. Appl Microbiol Biotechnol 97(8):3593– 3601. https://doi.org/10.1007/s00253-012-4603-1 40. Tamboli MS, Kulkarni MV, Deshmukh SP, Kale BB (2013) Synthesis and spectroscopic characterisation of silver–polyaniline nanocomposite. Mater Res Innov 17(2):112–116. https://doi. org/10.1179/1433075X12Y.0000000037 41. Tamboli MS, Kulkarni MV, Patil RH, Gade WN, Navale SC, Kale BB (2012) Nanowires of silver–polyaniline nanocomposite synthesized via in situ polymerization and its novel functionality as an antibacterial agent. Colloids Surf B 92:35–41. https://doi.org/10.1016/j. colsurfb.2011.11.006 42. Ivanova NM, Soboleva EA, Visurkhanova YA, Lazareva ES (2018) Structure-phase changes in polymer composites doped with silver nitrate and their electrocatalytic activity. Russ J Electrochem 54(11):999–1005. https://doi.org/10.1134/s1023193518130207 43. Zhou X, Liu Y, Du C, Ren Y, Mu T, Zuo P et al (2018) Polyaniline-encapsulated silicon on three-dimensional carbon nanotubes foam with enhanced electrochemical performance for lithium-ion batteries. J Power Sources 381:156–163. https://doi.org/10.1016/j.jpowsour. 2018.02.009 44. Patil DS, Shaikh JS, Pawar SA, Devan RS, Ma YR, Moholkar AV et al (2012) Investigations on silver/polyaniline electrodes for electrochemical supercapacitors. Phys Chem Chem Phys 14(34):11886–11895. https://doi.org/10.1039/C2CP41757J 45. Sun T, Seff K (1994) Silver clusters and chemistry in zeolites. Chem Rev 94(4):857–870. https://doi.org/10.1021/cr00028a001 46. Jin R, Cao Y, Mirkin CA, Kelly KL, Schatz GC, Zheng JG (2001) Photoinduced conversion of silver nanospheres to nanoprisms. Science 294(5548):1901–1903. https://doi.org/10.1126/ science.1066541 47. Lin JC, Wang CY (1996) Effects of surfactant treatment of silver powder on the rheology of its thick-film paste. Mater Chem Phys 45(2):136–144. https://doi.org/10.1016/0254-058 4(96)80091-5 48. Zhu Z, Kai L, Wang Y (2006) Synthesis and applications of hyperbranched polyesters— preparation and characterization of crystalline silver nanoparticles. Mater Chem Phys 96(2):447–453. https://doi.org/10.1016/j.matchemphys.2005.07.067 49. Leontidis E, Kleitou K, Kyprianidou-Leodidou T, Bekiari V, Lianos P (2002) Gold colloids from cationic surfactant solutions. 1. Mechanisms that control particle morphology. Langmuir 18(9):3659–3668. https://doi.org/10.1021/la011368s 50. Hoque J, Yadav V, Prakash RG, Sanyal K, Haldar J (2019) Dual-function polymer–silver nanocomposites for rapid killing of microbes and inhibiting biofilms. ACS Biomater Sci Eng 5(1):81–91. https://doi.org/10.1021/acsbiomaterials.8b00239 51. Meeporn K, Thongbai P (2019) Improved dielectric properties of poly(vinylidene fluoride) polymer nanocomposites filled with Ag nanoparticles and nickelate ceramic particles. Appl Surf Sci 481:1160–1166. https://doi.org/10.1016/j.apsusc.2019.03.191 52. Ren L, Zeng X, Zhang X, Sun R, Tian X, Zeng Y et al (2019) Silver nanoparticle-modified alumina microsphere hybrid composites for enhanced energy density and thermal conductivity. Compos A Appl Sci Manuf 119:299–309. https://doi.org/10.1016/j.compositesa.2019. 02.004

36

A. D. Kulkarni et al.

53. Chaudhary J, Tailor G, Kumar D (2019) Synthesis and characterization of silver-doped aniline formaldehyde nanocomposite: spectroscopic and microscopic studies. Res J Chem Environ 23(3):5 54. Parr RG (1983) Density functional theory. Annu Rev Phys Chem 34(1):631–656. https://doi. org/10.1146/annurev.pc.34.100183.003215 55. Parr RG, Yang W (1995) Density-functional theory of the electronic structure of molecules. Annu Rev Phys Chem 46(1):701–728. https://doi.org/10.1146/annurev.pc.46.100195.003413 56. Cohen AJ, Mori-Sánchez P, Yang W (2012) Challenges for density functional theory. Chem Rev 112(1):289–320. https://doi.org/10.1021/cr200107z 57. Perdew JP, Wang Y (1992) Accurate and simple analytic representation of the electron-gas correlation energy. Phys Rev B 45(23):13244–13249. https://doi.org/10.1103/PhysRevB.45. 13244 58. Perdew JP, Burke K, Ernzerhof M (1996) Generalized gradient approximation made simple. Phys Rev Lett 77(18):3865–3868. https://doi.org/10.1103/PhysRevLett.77.3865 59. Perdew JP, Ruzsinszky A (2010) Fourteen easy lessons in density functional theory. Int J Quant Chem 110(15):2801–2807. https://doi.org/10.1002/qua.22829 60. Becke AD (1993) Density-functional thermochemistry. III. The role of exact exchange. J Chem Phys 98(7):5648–5652. https://doi.org/10.1063/1.464913 61. Becke AD (1998) A new inhomogeneity parameter in density-functional theory. J Chem Phys 109(6):2092–2098. https://doi.org/10.1063/1.476722 62. Grimme S, Hansen A, Brandenburg JG, Bannwarth C (2016) Dispersion-corrected mean-field electronic structure methods. Chem Rev 116(9):5105–5154. https://doi.org/10.1021/acs.che mrev.5b00533 63. Zhao Y, Truhlar DG (2008) The M06 suite of density functionals for main group thermochemistry, thermochemical kinetics, noncovalent interactions, excited states, and transition elements: two new functionals and systematic testing of four M06-class functionals and 12 other functionals. Theor Chem Acc 120(1):215–241. https://doi.org/10.1007/s00214-0070310-x 64. Zhao Y, Truhlar DG (2008) Density functionals with broad applicability in chemistry. Acc Chem Res 41(2):157–167. https://doi.org/10.1021/ar700111a 65. Zhao Y, Truhlar DG (2008) Construction of a generalized gradient approximation by restoring the density-gradient expansion and enforcing a tight Lieb–Oxford bound. J Chem Phys 128(18):184109. https://doi.org/10.1063/1.2912068 66. Zhao Y, Truhlar DG (2011) Applications and validations of the Minnesota density functionals. Chem Phys Lett 502(1):1–13. https://doi.org/10.1016/j.cplett.2010.11.060 67. Zhao Y, Truhlar DG (2005) Design of density functionals that are broadly accurate for thermochemistry, thermochemical kinetics, and nonbonded interactions. J Phys Chem A 109(25):5656–5667. https://doi.org/10.1021/jp050536c 68. Peverati R, Truhlar DG (2011) Quest for a universal density functional: the accuracy of density functionals across a broad spectrum of databases in chemistry and physics. Philos Trans R Soc A Math Phys Eng Sci 372(2011):20120476. https://doi.org/10.1098/rsta.2012.0476 69. Ziegler T (1991) Approximate density functional theory as a practical tool in molecular energetics and dynamics. Chem Rev 91(5):651–667. https://doi.org/10.1021/cr00005a001 70. Barner-Kowollik C, Buback M, Charleux B, Coote ML, Drache M, Fukuda T et al (2006) Mechanism and kinetics of dithiobenzoate-mediated RAFT polymerization. I. The current situation. J Polym Sci Part A Polym Chem 44(20):5809–5831. https://doi.org/10.1002/pola. 21589 71. Noble BB, Coote ML (2020) Isotactic regulation in the radical polymerization of calcium methacrylate: is multiple chelation the key to stereocontrol? J Polym Sci 58(1):52–61. https:// doi.org/10.1002/pola.29324 72. Gartner TE, Jayaraman A (2019) Modeling and simulations of polymers: a roadmap. Macromolecules 52(3):755–786. https://doi.org/10.1021/acs.macromol.8b01836 73. Frischknecht AL, Curro JG, Frink LJD (2002) Density functional theory for inhomogeneous polymer systems. II. Application to block copolymer thin films. J Chem Phys 117(22):10398– 10411. https://doi.org/10.1063/1.1518686

Growth and Spectral Features of Silver-Doped Aniline …

37

74. Wu J, Li Z (2007) Density-functional theory for complex fluids. Annu Rev Phys Chem 58(1):85–112. https://doi.org/10.1146/annurev.physchem.58.032806.104650 75. McMullen WE, Oxtoby DW (1987) A density functional approach to freezing transitions in molecular fluids: dipolar hard spheres. J Chem Phys 86(7):4146–4156. https://doi.org/10. 1063/1.451925 76. Woodward CE, Yethiraj A (1994) Density functional theory for inhomogeneous polymer solutions. J Chem Phys 100(4):3181–3186. https://doi.org/10.1063/1.466409 77. Qi H, Zhong C (2008) Density functional theory studies on the microphase separation of amphiphilic comb copolymers in a selective solvent. J Phys Chem B 112(35):10841–10847. https://doi.org/10.1021/jp0774950 78. Melenkevitz J, Muthukumar M (1991) Density functional theory of lamellar ordering in diblock copolymers. Macromolecules 24(14):4199–4205. https://doi.org/10.1021/ma0001 4a038 79. Jawalkar SS, Raju, Halligudi SB, Sairam M, Aminabhavi TM (2007) Molecular modeling simulations to predict compatibility of poly(vinyl alcohol) and chitosan blends: a comparison with experiments. J Phys Chem B 111(10):2431–2439. https://doi.org/10.1021/jp0668495 80. Wu D, Truhlar DG (2021) How accurate are approximate density functionals for noncovalent interaction of very large molecular systems? J Chem Theory Comput 17(7):3967–3973. https://doi.org/10.1021/acs.jctc.1c00162 81. Sharma P, Bao JJ, Truhlar DG, Gagliardi L (2021) Multiconfiguration pair-density functional theory. Annu Rev Phys Chem 72(1):541–564. https://doi.org/10.1146/annurev-physchem-090 419-043839 82. Zhang D, Hermes MR, Gagliardi L, Truhlar DG (2021) Multiconfiguration density-coherence functional theory. J Chem Theory Comput 17(5):2775–2782. https://doi.org/10.1021/acs.jctc. 0c01346 83. Janesko BG, Verma P, Scalmani G, Frisch MJ, Truhlar DG (2020) M11plus, a range-separated hybrid meta functional incorporating nonlocal Rung-3.5 correlation, exhibits broad accuracy on diverse databases. J Phys Chem Lett 11(8):3045–3050. https://doi.org/10.1021/acs.jpclett. 0c00549 84. Yu HS, Li SL, Truhlar DG (2016) Perspective: Kohn-Sham density functional theory descending a staircase. J Chem Phys 145(13):130901. https://doi.org/10.1063/1.4963168 85. Dahlke EE, Truhlar DG (2006) Assessment of the pairwise additive approximation and evaluation of many-body terms for water clusters. J Phys Chem B 110(22):10595–10601. https:// doi.org/10.1021/jp061039e 86. Dahlke EE, Truhlar DG (2007) Electrostatically embedded many-body expansion for large systems, with applications to water clusters. J Chem Theory Comput 3(1):46–53. https://doi. org/10.1021/ct600253j 87. Dahlke EE, Truhlar DG (2007) Electrostatically embedded many-body correlation energy, with applications to the calculation of accurate second-order Møller−Plesset perturbation theory energies for large water clusters. J Chem Theory Comput 3(4):1342–1348. https://doi. org/10.1021/ct700057x 88. Dahlke EE, Leverentz HR, Truhlar DG (2008) Evaluation of the electrostatically embedded many-body expansion and the electrostatically embedded many-body expansion of the correlation energy by application to low-lying water hexamers. J Chem Theory Comput 4(1):33–41. https://doi.org/10.1021/ct700183y 89. Dahlke EE, Truhlar DG (2008) Electrostatically embedded many-body expansion for simulations. J Chem Theory Comput 4(1):1–6. https://doi.org/10.1021/ct700223r 90. Cramer CJ, Truhlar DG (2009) Density functional theory for transition metals and transition metal chemistry. Phys Chem Chem Phys 11(46):10757–10816. https://doi.org/10.1039/B90 7148B 91. Alecu IM, Zheng J, Zhao Y, Truhlar DG (2010) Computational thermochemistry: scale factor databases and scale factors for vibrational frequencies obtained from electronic model chemistries. J Chem Theory Comput 6(9):2872–2887. https://doi.org/10.1021/ct100326h

38

A. D. Kulkarni et al.

92. Kulkarni AD, Truhlar DG (2011) Performance of density functional theory and Møller–Plesset second-order perturbation theory for structural parameters in complexes of Ru. J Chem Theory Comput 7(7):2325–2332. https://doi.org/10.1021/ct200188n 93. Kulkarni AD, Truhlar DG, Goverapet Srinivasan S, van Duin ACT, Norman P, Schwartzentruber TE (2013) Oxygen interactions with silica surfaces: coupled cluster and density functional investigation and the development of a new ReaxFF potential. J Phys Chem C 117(1):258–269. https://doi.org/10.1021/jp3086649 94. Leverentz HR, Siepmann JI, Truhlar DG, Loukonen V, Vehkamäki H (2013) Energetics of atmospherically implicated clusters made of sulfuric acid, ammonia, and dimethyl amine. J Phys Chem A 117(18):3819–3825. https://doi.org/10.1021/jp402346u 95. Kulkarni AD (2021) Unraveling hydrogen bonded clustering with water: density functional theory perspective. In: Glossman-Mitnik D (ed) Density functional theory—recent advances, new perspectives and applications. Intech Open, London. https://doi.org/10.5772/intechopen. 99958 96. Kulkarni AD (2019) Molecular hydration of carbonic acid: ab initio quantum chemical and density functional theory investigation. J Phys Chem A 123(26):5504–5516. https://doi.org/ 10.1021/acs.jpca.9b01122 97. Weigend F, Ahlrichs R (2005) Balanced basis sets of split valence, triple zeta valence and quadruple zeta valence quality for H to Rn: design and assessment of accuracy. Phys Chem Chem Phys 7(18):3297–3305. https://doi.org/10.1039/B508541A 98. Frisch MJ, Trucks GW, Schlegel HB, Scuseria GE, Robb MA, Cheeseman JR et al (2009) Gaussian 09 Revision E, 01 edn. Gaussian Inc. Wallingford, CT 99. Scrocco E, Tomasi J (1978) Electronic molecular structure, reactivity and intermolecular forces: an euristic interpretation by means of electrostatic molecular potentials. In: Löwdin P-O (ed) Advances in quantum chemistry. Academic Press, pp 115–193 100. Cancès E, Mennucci B, Tomasi J (1997) A new integral equation formalism for the polarizable continuum model: theoretical background and applications to isotropic and anisotropic dielectrics. J Chem Phys 107(8):3032–3041. https://doi.org/10.1063/1.474659 101. Tomasi J, Mennucci B, Cancès E (1999) The IEF version of the PCM solvation method: an overview of a new method addressed to study molecular solutes at the QM ab initio level. J Mol Struct Theochem 464(1):211–226. https://doi.org/10.1016/S0166-1280(98)00553-3 102. Bader RFW (1985) Atoms in molecules. Acc Chem Res 18(1):9–15. https://doi.org/10.1021/ ar00109a003 103. Gadre SR, Shirsat RN, Limaye AC (1994) Molecular tailoring approach for simulation of electrostatic properties. J Phys Chem 98(37):9165–9169. https://doi.org/10.1021/j10008 8a013 104. Mehta G, Gunasekaran G, Gadre SR, Shirsat RN, Ganguly B, Chandrasekhar J (1994) Electrophilic additions to 7-methylenenorbornenes and 7-isopropylidenenorbornenes: can remote substituents swamp electrostatic control of .pi.-face selectivity? J Org Chem 59(8):1953–1955. https://doi.org/10.1021/jo00087a001 105. Gejji SP, Suresh CH, Babu K, Gadre SR (1999) Ab initio structure and vibrational frequencies of (CF3 SO2 )2 N-Li+ ion pairs. J Phys Chem A 103(37):7474–7480. https://doi.org/10.1021/ jp984474k 106. Gadre SR, Kulkarni AD (2000) Electrostatics for exploring hydration patterns of molecules: 2. Formamide. Ind J Chem 39A:9. http://nopr.niscair.res.in/handle/123456789/25777 107. Sivanesan D, Babu K, Gadre SR, Subramanian V, Ramasami T (2000) Does a stacked DNA base pair hydrate better than a hydrogen-bonded one? An ab initio study. J Phys Chem A 104(46):10887–10894. https://doi.org/10.1021/jp0016986 108. Gadre SR, Babu K, Rendell AP (2000) Electrostatics for exploring hydration patterns of molecules. 3. Uracil. J Phys Chem A 104(39):8976–8982. https://doi.org/10.1021/jp001146n 109. Maheshwary S, Patel N, Sathyamurthy N, Kulkarni AD, Gadre SR (2001) Structure and stability of water clusters (H2 O)n, n = 8−20: an ab initio investigation. J Phys Chem A 105(46):10525–10537. https://doi.org/10.1021/jp013141b

Growth and Spectral Features of Silver-Doped Aniline …

39

110. Sundararajan K, Sankaran K, Viswanathan KS, Kulkarni AD, Gadre SR (2002) H−π Complexes of acetylene−ethylene: a matrix isolation and computational study. J Phys Chem A 106(8):1504–1510. https://doi.org/10.1021/jp012457g 111. Sundararajan K, Viswanathan KS, Kulkarni AD, Gadre SR (2002) H· · · π complexes of acetylene–benzene: a matrix isolation and computational study. J Mol Struct 613(1):209–222. https://doi.org/10.1016/S0022-2860(02)00180-1 112. Mehta G, Singh SR, Balanarayan P, Gadre SR (2002) Electrophilic additions to a 2methylenebicyclo[2.1.1]hexane system: probing π-face selectivity for electrostatic and orbital effects. Org Lett 4(14):2297–2300. https://doi.org/10.1021/ol026005d 113. Kulkarni AD, Babu K, Gadre SR, Bartolotti LJ (2004) Exploring hydration patterns of aldehydes and amides: ab initio investigations. J Phys Chem A 108(13):2492–2498. https://doi. org/10.1021/jp0368886 114. Balanarayan P, Gadre SR (2005) Why are carborane acids so acidic? An electrostatic interpretation of Brønsted acid strengths. Inorg Chem 44(26):9613–9615. https://doi.org/10.1021/ ic051347b 115. Yeole SD, Gadre SR (2011) Topography of scalar fields: molecular clusters and π-conjugated systems. J Phys Chem A 115(45):12769–12779. https://doi.org/10.1021/jp2038976 116. Gadre SR, Yeole SD, Sahu N (2014) Quantum chemical investigations on molecular clusters. Chem Rev 114(24):12132–12173. https://doi.org/10.1021/cr4006632 117. Kulkarni AD, Rai D, Bartolotti LJ, Pathak RK (2006) Interaction of peroxyformic acid with water molecules: a first-principles study. J Phys Chem A 110(42):11855–11861. https://doi. org/10.1021/jp0641536 118. Kulkarni AD, Rai D, Bartolotti LJ, Pathak RK (2009) Microsolvation of methyl hydrogen peroxide: ab initio quantum chemical approach. J Chem Phys 131(5):054310. https://doi.org/ 10.1063/1.3179753 119. Ganesh V (2009) MeTA studio: a cross platform, programmable IDE for computational chemist. J Comput Chem 30(4):661–672. https://doi.org/10.1002/jcc.21088 120. Sahu N, Gadre SR (2014) Molecular tailoring approach: a route for ab initio treatment of large clusters. Acc Chem Res 47(9):2739–2747. https://doi.org/10.1021/ar500079b

Evaluation of Machining Performance and Parametric Optimization During Drilling of Bio-nanocomposite Umang Dubey, Jogendra Kumar, Prakhar Kumar Kharwar, and Rajesh Kumar Verma

1 Introduction Poly(methyl methacrylate) (PMMA) has outstanding properties like clarity, high elastic elasticity, hardness, and lightness making it an ideal material for implant applications [1]. The standard method of implant fixation is to employ an acrylic cement mostly comprised of poly(methy1 methacrylate) (PMMA) [2, 3]. An extensive range of nanofillers, such as carbon nanotubes, [4] titanium oxide [5], zirconium oxide [6], hydroxyapatite [7] polymeric nanofibers were utilized as reinforcement to enhance the mechanical properties of acrylic cement [8]. Hydroxyapatite (HA) which has the general formula Ca10 (PO4 )6 (OH)2 is a biocompatible material that merges well with the composition of bone, as it has adequate osteoconductive properties. As a consequence, adding HA in bone cement formulations improves biocompatibility and mechanical strength [8–10]. The mechanical properties of hydroxyapatite-filled bone cement produced with functionalized methacrylate suggest that it has a broader range of applications [11]. According to these researches, adding hydroxyapatite to PMMA cement enhances its mechanical characteristics, depending on the concentration. These findings also imply that little research has been conducted on the aspects of machining of HAPMMA bone cement composite, such that the composite can be utilized as a substitute for real bone. Drilling is the most frequent form of fabrication, notably for biomaterials and artificial implants [12]. When utilizing PMMA bone cement to put bolts for safety and fixation, drilling on the prosthesis is commonly necessary [13]. As a U. Dubey · J. Kumar · R. K. Verma (B) Materials and Morphology Laboratory, Department of Mechanical Engineering, Madan Mohan Malaviya University of Technology, Gorakhpur, U.P 273010, India e-mail: [email protected] P. K. Kharwar Department of Mechanical Engineering, Sobhasaria Engineering College, Sobhasaria Group of Institutions, Sikar, Rajasthan 332001, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_4

41

42 Table 1 Classification of prepared samples

U. Dubey et al. Sample

PH-1

PH-2

PH-3

HA wt.%

4

10

16

result, optimum drilling settings must be evaluated while developing PMMA bone cement nanocomposite for enhanced performance in implant applications. In the current work, the preference selection index (PSI) optimization module is used to find an optimal parametric arrangement for ideal machining constraints with desired outcomes. The considered variables in the process in this investigation are speed of spindle, reinforcement (HA) weight %, and drill bit material. Surface roughness (Sr) and circularity error (C er ) were investigated as well as the influence of process factors on response characteristics. The effects of experiment input factors on machining efficiency were measured using ANOVA. An interaction plot study is performed to identify the impact of HA wt.% on the Sr and Cer.

2 Materials and Method of Preparation The HA-PMMA nanocomposites were developed with commercially available Simplex© PMMA bone cement from Global Corporation in Ahmedabad, India, hydroxyapatite nanoparticles of 99% purity, and spherical morphology of 20–80 nm from Ad Nano in Karnataka, India, and concentrated NH4 OH from the scientific unit store in Varanasi, Uttar Pradesh, India. PMMA bone cement was substituted with a weighted equivalent component of HA after mixing HA powder in a concentrated NH4 OH solution. In the experiment, hydroxyapatite nanoparticle fillers were used to replace 16, 10, and 4 wt.% of the PMMA bone cement available in powder form. M/P = 0.5 was used to balance the liquid monomer (M) to the PMMA powder (P). For 1 h, the developed dough should be maintained at room temperature in the mold. The generated samples were classified into three groups (PH1, PH2, and PH3) based on the weight percent indicated in Table 1. PH stands for PMMA bone cement with hydroxyapatite reinforcement.

3 Experimental The drilling operation on the HA-PMMA nanocomposite is carried out using a manually driven vertical drilling machine in the experiment. Figure 1 shows a schematic representation of the vertical drilling machine used in the experiment. Table 2 displayed machining parameters such as HA weight %, speed of spindle, and drill bit material at three distinct levels.

Evaluation of Machining Performance and Parametric Optimization …

43

Fig. 1 Vertical drilling machine

Table 2 Process parameters and their levels

Process parameters

Level Higher

Lower

Medium

Speed of spindle (SPEED) 1428

318

865

HA wt.% (Wt.%)

16

4

10

Drill bit material (TOOL)

TiAlN (3) HSS (1) Carbide (2)

3.1 Experiment Design Using the Taguchi Approach The Taguchi-based L9 orthogonal array is employed to determine the drilling conditions in this work. Using analysis of variance (ANOVA) and Taguchi optimization, the influence of drilling parameters on the values of Sr and C er was studied.

3.2 Surface Roughness Calculation A Mitutoyo Surftest SJ-201 Series 178-compact surface roughness test device calculates the mean surface roughness (Sr). For each estimation, the cut-off and testing lengths are 0.8 and 5 mm, respectively.

44

U. Dubey et al.

Fig. 2 Circularity error

3.3 Circularity Error Calculation Equation (1) is used to evaluate the circularity error of the hole. Cer = Dmax − Dmin

(1)

where Dmin and Dmax are the minimum and maximum sizes of the hole at the entry which are indicated in Fig. 2.

3.4 ANOVA Analysis The use of analysis of variance was necessary to examine the effects of process factors on responses and identify notable process boundaries using a mathematical model. To get the optimal yield, each research was conducted with the assumption of a 95% confidence level. The aftereffect of the circularity error and the surface roughness test is indicated in Table 3 showing ANOVA findings. The ANOVA equations of surface roughness and circularity error can be utilized to find all the parameters’ significance. The model summary showed an R-sq value above 95%, which ensures the model’s feasibility.

4 Optimization Methodology The selection of an optimum parametric combination is difficult in drilling because it involves many data measurement parameters and answers obtained from many

Evaluation of Machining Performance and Parametric Optimization …

45

Table 3 ANOVA results Response

Equation

Summary

Surface roughness 3.410 + 0.841 SPEED_318.0000 + 0.170 SPEED_865.0000 − 1.011 SPEED_1428.0000 −0.111 wt.%_4.0000 − 0.024 wt.%_10.0000 + 0.135 wt.%_16.0000 + 0.112 TOOL_1.0000 − 0.121 TOOL_2.0000 + 0.009 TOOL_3.0000 Circularity Error

R-sq = 95.08%, R-sq(adj) = 80.30%

0.025078+ 0.00946 SPEED_318.0000 − R-sq = 97.98%, 0.00601 SPEED_865.0000 − R-sq(adj) = 91.92% 0.00344 SPEED_1428.0000 +0.00216 wt.%_4.0000 − 0.00168 wt.%_10.0000 − 0.00048 wt.%_16.0000 + 0.00099 TOOL_1.0000 − 0.00108 TOOL_2.0000 + 0.00009 TOOL_3.0000

trials. The preference selection index (PSI) multicriteria decision making (MCDM) technique facilitates optimum parameter selection.

4.1 Preference Selection Index Method Maniya and Bhatt [14] introduced the preference selection index (PSI) technique in 2010 to solve material selection MCDM issues. Unlike other MCDM methods, the PSI approach does not require determining the relative significance of the criteria and hence does not require determining criteria weights. As a result, the approach is particularly effective in situations when there is a conflict over the relative relevance of criteria. The step-by-step method for PSI is detailed on the following pages. Steps in Preference Selection Index (PSI) technique. Step-1: Using the following formulae, compute the normalized values. In order to maximize (beneficial) criteria: Xij =

xi j , i = 1, . . . , m ximax j

(2)

in order to minimize (non-beneficial) criteria: Xij =

ximin j xi j

, i = 1, . . . , m

(3)

where xi j is the ith alternative’s assessment value in relation to the jth criterion; m is the number of options. Step 2: Using the equation below, get the mean values of normalized performances in relation to each criterion.

46

U. Dubey et al.

N=

m 1 Xij n i=1

(4)

where n is the number of criteria. Step 3: Using the equation below, get the values of the variation of preferences with respect to each criterion. ∅j =

m  

Xij − N

2

(5)

i=1

Step 4: Using the following equation, find the variations in the value of the preference with respect to each criterion. ϕj = 1 − ∅j

(6)

Step 5: Calculate the weights of the criterion using the following formula. ϕj w j = n j=1

ϕj

(7)

Step 6: Using the following equation, calculate the preferred selection index of options. θi =

n 

Xijwj

(8)

j=1

Step 7: Determine the entire ranking of alternatives based on the preference selection index values of the alternatives. The alternative with the highest preference selection index is the best overall option.

5 Results and Discussion 5.1 Influence of Hydroxyapatite Content on Responses The influence of HA content on the responses is evaluated with the help of plotting an interaction plot between wt.% and responses at constant tool material and constant spindle speed. In Fig. 3a, 10 wt.% of HA shows the least value of surface roughness using the HSS tool, and in Fig. 3b also, 10 wt.% of HA shows the least value at 1428 rpm of spindle speed. The ideal input parameter is a high spindle speed [15]. In Fig. 4a, 10 wt.% of HA shows the least value of circularity error at 865 rpm of

Evaluation of Machining Performance and Parametric Optimization …

47

Fig. 3 Interaction plot of Sr with wt.% a at constant tool material, b at a constant speed

Fig. 4 Interaction plot of Ce with wt.% a at a constant speed, b at constant tool material

spindle speed. In Fig. 4b, using the TiAlN tool, 10 wt.% of HA offers the least value. A polymer matrix HA reinforced composite has a similar effect [16].

48

U. Dubey et al.

Table 4 Preference selection index values Exp. No

Spidle speed (SPEED)

HA wt.% (Wt.%)

Tool material (TOOL)

Surface roughness (Sr)

Circularity error (C er )

Preferred selection index (θi )

1

318.0

4.0

HSS

4.361

0.039

0.499

2

318.0

10.0

Carbide

4.245

0.031

0.564

3

318.0

16.0

TiAlN

4.145

0.033

0.551

4

865.0

4.0

Carbide

3.098

0.019

0.838

5

865.0

10.0

TiAlN

3.675

0.018

0.789

6

865.0

16.0

HSS

3.967

0.018

0.765

7

1428.0

4.0

TiAlN

2.436

0.023

0.870

8

1428.0

10.0

HSS

2.236

0.020

0.970

9

1428.0

16.0

Carbide

2.523

0.021

0.882

5.2 Preference Selection Index (PSI) Method The PSI module is used to optimize the drilling operation once all of the response parameters have been calculated. Using Eqs. 2–8, the PSI selection index is calculated, then ranked from lower to the highest value. All the 9 experiment PSI selection index value is mentioned in Table 4. The findings of PSI module optimal conditions are remarked with a maximum value of preference selection index (0.970) as HA (10 wt.%), speed of spindle (1428 RPM), and drill bit material (HSS). Drilling experimental outcomes are improved with a 10% hydroxyapatite (HA) content in polymer composite [16]. When drilling poly-methyl methacrylate (PMMA)-based composites, a faster spindle speed gives the best results [17]. When the spindle speed is increased, the surface roughness (Sr) improves [18]. Compared to earlier work in the same region, it can be concluded that the optimized experiment achieved using the PSI technique is useful in practical work and that this method may be used for other machining optimization issues.

6 Confirmatory Test HA-PMMA nanocomposites were used in the affirmation test, which showed to be the most influential metric for determining behavior response. The optimum set of input parameters was found by experiment no. 8 using the PSI optimization approach. The best parametric setting among the performed tests is wt.% -10/TOOL-1/SPEED1428. wt.% -16/TOOL-3/SPEED-865 is the best solution obtained using Taguchi L9 orthogonal array. It has been proven that when the optimization approach is used, the Sr and C er of the process are significantly improved. Sr falls from 3.245 µm to 2.236 µm showing 31.09%, and C er falls from 0.034 to 0.020 showing 41.17%.

Evaluation of Machining Performance and Parametric Optimization …

49

7 Conclusion In this study, the preference selection index (PSI) technique was used to obtain the optimum parameter setting for drilling HA-PMMA nanocomposites. The PSI technique has been successfully utilized to choose control variables, levels, and the best machining environment for reduced surface roughness (Sr) and circularity error (C er ) which was also confirmed with the help of a confirmatory test. The conclusions are drawn from the examination. With the use of the PSI method, it was possible to aggregate various responses such as Sr and C er into a single objective function, a standard performance measure. 10 wt. % (Level 2), 1428 rpm (Level 3), and HSS tool material are the optimal combination of machining characteristics analyzed using PSI. The important machining factors and their influences on response parameters, namely Sr and C er , are identified using ANOVA analysis. Spindle speed came out to be the most influencing parameter for both Sr and C er . PSI significantly increases Sr estimates by 31.09% and 41.17% of C er compared to the Taguchi orthogonal results. These results show greater applicability of the PSI method in machining optimization problems. Interaction plot analysis suggests the 10 wt.% HA to be optimum for surface roughness and circularity error. Acknowledgements The authors would like to express their gratitude to the Madan Mohan Malaviya University of Technology in Gorakhpur, Uttar Pradesh.

References 1. Xi GX, Song SL, Liu Q (2005) Catalytic effects of sulfates on thermal degradation of waste poly (methyl methacrylate). Thermochim Acta 435(1):64–67 2. Charnley J (1970) The reaction of bone to self-curing acrylic cement: a long-term histological study in man. J Bone Joint Surg. British volume 52(2):340–53 3. Kamaraj M, Santhanakrishnan R, Muthu E (2018) Investigation of surface roughness and MRR in drilling of Al2 O3 particle and sisal fibre reinforced epoxy composites using TOPSIS based Taguchi method. IOP Conf Ser Mater Sci Eng 402(1). IOP Publishing 4. Marrs B, Andrews R, Rantell T, Pienkowski D (2006) Augmentation of acrylic bone cement with multiwall carbon nanotubes. J Biomed Mater Res Part A 77(2):269–276 5. Khaled SMZ, Charpentier PA, Rizkalla AS (2011) Physical and mechanical properties of PMMA bone cement reinforced with nano-sized Titania fibers. J Biomater Appl 25(6):515–537 6. Kane RJ, Yue W, Mason JJ, Roeder RK (2010) Improved fatigue life of acrylic bone cements reinforced with zirconia fibers. J Mech Behav Biomed Mater 3(7):504–511 7. Giunti A, Moroni A, Olmi R, Vicenzi G (1983) Composite acrylic cement with added hydroxyapatite: a study of the polymerization temperature. Ital J Orthop Traumatol 9(3):369–375 8. Slane J, Vivanco J, Ebenstein D, Squire M, Ploeg HL (2014) Multiscale characterization of acrylic bone cement modified with functionalized mesoporous silica nanoparticles. J Mech Behav Biomed Mater 37:141–152 9. Puska MA, Lassila LV, Närhi TO, Yli-Urpo AUO, Vallittu PK (2004) Improvement of mechanical properties of oligomer-modified acrylic bone cement with glass-fibers. Appl Compos Mater 11

50

U. Dubey et al.

10. Dalby MJ, Di Silvio L, Harper EJ, Bonfield W (2001) Initial interaction of osteoblasts with the surface of a hydroxyapatite-poly (methylmethacrylate) cement. Biomaterials 22(13):1739– 1747 11. Islas-Blancas ME, Cervantes-Uc JM (2001) Characterization of bone cements prepared with functionalized methacrylates and hydroxyapatite. J Biomater Sci Polym Ed 12(8):893–910 12. Khorasani AM, Gibson I, Goldberg M, Nomani J, Littlefair G (2016) Machinability of metallic and ceramic biomaterials: a review. Sci Adv Mater 8(8) 13. Varma AK, Varma V, Mangalandan TS, Bal A, Kumar H (2014) Use of polymethyl methacrylate as prosthetic replacement of destroyed foot bones–clinical audit 14. Maniya K, Bhatt MG (2010) A selection of material using a novel type decision-making method: preference selection index method. Mater Des 31(4):1785–1789 15. Mehar AK, Kotni S (2018) Development and machining analysis of hydroxyapatite and polypropylene composite for biomedical applications. Int J Adv Res Sci Eng Technol 5 16. Mehar AK, Kotni S, Mahapatra SS, Patel SK (2020) A comparative study on drilling performance of hydroxyapatite-polycarbonate and hydroxyapatite-polysulfone composites using principal component analysis methodology for orthopaedic applications. Mater Today Proc 33:5174–5178 17. Bagal DK, Panda SK, Barua A, Jeet S, Pattanaik AK, Patnaik D (2021) Parametric appraisal of CNC micro-drilling of aerospace material (PMMA) using Taguchi-based EDAS method. In: Advances in mechanical processing and design. Springer, Singapore, pp 449–458 18. Kamaraj M, Santhanakrishnan R, Muthu E (2018) Investigation of surface roughness and MRR in drilling of Al2 O3 particle and sisal fibre reinforced epoxy composites using TOPSIS based Taguchi method. IOP Conf Ser Mater Sci Eng 402(1)

Polymeric Lipid Nanoparticles for Donepezil Delivery Meghana Bhandari, Nahida Rasool, and Yashveer Singh

1 Introduction Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the degradation of neurotransmitters, loss of synapses, and neuronal apoptosis, leading to a severe impairment of memory, defective cognition, and inability to perform familiar tasks [1]. A hallmark of this disease is the accumulation of protein beta-amyloid plaques outside neurons and twisted strands of tau protein inside neurons within the brain [1]. Currently, there is no actual curative treatment for AD, and only the symptomatic therapy is available for managing it. The incidence of Alzheimer’s disease (AD) in the human population has remained a concern over the years, particularly in emerging countries with increasing population of senior citizens [2]. It is estimated that the number of people affected by AD, as well as the mortality rate associated with it, is going to surge in near future [3]. Donepezil hydrochloride is a lipophilic drug that is administered via the oral route in the form of solid oral dosages or orally disintegrating tablets for the treatment of AD [4]. It is a potent, selective, and reversible inhibitor of acetylcholinesterase (AChE), which is an enzyme involved in catalyzing the breakdown of acetylcholine and other neurotransmitters within the body [2]. However, the oral administration of drug intended for delivery to brain is followed by the first-pass metabolism and an encounter with the BBB, which leads to a low bioavailability and decreased concentration at the site of action [5]. Therefore,

Meghana Bhandari and Nahida Rasool-both authors contributed equally to the work M. Bhandari · N. Rasool · Y. Singh (B) Department of Biomedical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India e-mail: [email protected] Y. Singh Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_5

51

52

M. Bhandari et al.

there is a need for the repeated dosage to maintain the therapeutic effect of drug, which in turn leads to side effects, like diarrhea, vomiting, nausea, and anorexia. There is a need to develop an efficient carrier system and explore other routes of administration for better therapeutic effects [4, 6]. The intranasal drug delivery offers an excellent route to deliver drugs directly to the brain via olfactory and trigeminal nerve pathways that originate in the nasal cavity and terminate in the brain [7]. This route not only avoids the first-pass metabolism but also reduces the drug distribution to non-target sites, thereby facilitating rapid drug absorption, higher bioavailability at the site of action, rapid onset of action, and decreased side effects [7]. The nasal mucosa is highly vascular, and it possesses a negatively charged mucus and narrow pathways, with pH in the range of 4.5–6.5 [8]. Thus, nanoemulsion systems, like solid lipid nanoparticles, nanostructured lipid carriers, polymeric micelles, or polymeric nanoparticles, can be used to effectively deliver drugs directly to the brain. Chitosan is a highly biocompatible, biodegradable, and mucoadhesive polymer, and this amino polysaccharide electrostatically interacts with the negatively charged nasal membrane and aggregates mucin particles. Soy lecithin is a naturally occurring phospholipid that is biocompatible, shows a higher degree of lipophilic drug loading, and ensures a prolonged drug release [9]. Gelatin is a biocompatible polymer and has low antigenicity and high propensity for chemical modifications [10–12]. Polymer lipid nanoparticles, such as chitosan lecithin, have been used as an effective transdermal [13], ocular [14], and intranasal drug delivery vehicle [9], whereas gelatin lecithin nanoparticles have been explored for the transdermal [15] and oral drug administration [16]. Based on these considerations, we were interested in investigating the gelatin lipid nanoparticulate system for intranasal application. In this study, we have formulated two mucoadhesive nanoparticulate systems, chitosan lecithin (L-CS) and gelatin lecithin (Ge-L), for the donepezil loading and delivery. Lipidic systems, such as solid lipid nanoparticles, have been used for intranasal delivery to the brain and showed efficient brain targeting [9, 17]. Combining a lipid and a hydrophilic polymer will form a nanoemulsion with enhanced mucoadhesion required for the intranasal drug delivery. The system is intended for the intranasal delivery of donepezil in order to achieve an efficient drug release at the site of action.

2 Materials and Methods 2.1 Materials Chitosan (ï = 200–600 mPas) and lecithin (from soybean) were obtained from the Tokyo Chemical Industry, Tokyo, Japan; methanol AR from S.D. Fine Chem, Chandigarh, Punjab; chloroform and acetone from the Fischer Scientific, Mumbai; Type I water, glacial acetic acid, hydrochloric acid (HCl), anhydrous sodium acetate, and dimethyl sulfoxide (DMSO) from the Merck Life Science, Mumbai; gelatin (extra pure, bacteriological grade), MTT reagents, mucin (Type III from the porcine

Polymeric Lipid Nanoparticles for Donepezil Delivery

53

stomach), and Bradford reagents from the Himedia Laboratories, Mumbai; and glutaraldehyde (25% in water) from the Avra Synthesis, Hyderabad.

2.2 Methods 2.2.1

Fabrication of L-CS NPs

Soy lecithin (40 mg) was weighed and dissolved in a solvent mixture of methanol and chloroform (1 mL). Chitosan (4 mg) was dissolved in an aqueous solution of glacial acetic acid (1% v/v, 1 mL). Both solutions were completely homogenized using a probe sonicator [14]. The lecithin solution (4% w/v, 40 mg/mL) was injected into the chitosan solution (0.4%, w/v) to obtain a final volume of 10 mL, and the resulting emulsion was stirred for 30 min. After 10 min, glutaraldehyde (1% v/v, 200 μL) was added into the mixture to ensure crosslinking. The resulting emulsion was centrifuged at 8000 rpm for 10 min and washed with water and ethanol to remove unreacted polymers. The product was obtained as a sticky precipitate on the walls of the centrifuge tube.

2.2.2

Fabrication of Ge-L NPs

The fabrication of gelatin lecithin was done using the desolvation method as per the earlier report [16]. Briefly, gelatin (50 mg) was weighed and dissolved in 2.5 mL of Type I deionized water. Lecithin (2.5 mg) was weighed and dissolved in a solution of equal volumes of methanol and chloroform (0.75 mL). Gelatin solution (2% w/v, 100 mg/5 mL) was completely dissolved at 37 °C using a shaking incubator, and the other two solutions were completely dissolved using a probe sonicator. Cold acetone (2.5 mL) was added as a desolvating agent to the gelatin solution for the precipitation to occur, followed by the addition of water to dissolve precipitates. The pH of the gelatin solution was adjusted to 3.6 using the HCl solution (0.2 M). The lecithin solution (0.33% w/v, 2.5 mg in 0.7 mL) was added dropwise to the gelatin solution and stirred for about 12 h, to allow for the evaporation of methanol. Next, acetone (2.5 mL) was added to the solution along with the glutaraldehyde (0.04%, v/v) for crosslinking the particles. The mixture was stirred for another 12 h, centrifuged at 8000 rpm (0 °C, 10 min), and washed twice with water and ethanol to obtain the particles.

54

2.2.3

M. Bhandari et al.

Characterization

FTIR Analysis The chemical nature of samples was confirmed by FTIR spectroscopy, using a Bruker Tensor F27 spectroscope (ATR mode).

Particle Size Distribution and Zeta Potential Measurements The mean particle size and zeta potential of nanoparticulate systems were determined using a DLS (Microtrac Flex).

SEM Study All samples for SEM analysis were prepared by allowing a single drop of nanoparticle suspension, which was dried overnight at room temperature, mounted on a platinumcoated copper stub at a voltage of 10 kV, and then imaged on the scanning electron microscope (SEM, JEOL JSM-6610LV).

2.2.4

Donepezil-Loaded NPs

Drug-loaded nanoparticles were fabricated in the same manner as blank nanoparticles, and donepezil (with different concentrations) was added to the organic solvent mixture of methanol and chloroform [16, 17].

2.2.5

Loading Efficacy

The L-CS NPs and donepezil-loaded L-CS NPs were suspended in a solution mixture of methanol and glacial acetic acid (10%, v/v), and the same procedure was used for the Ge-L NPs and donepezil-loaded Ge-L NPs. These solutions were homogenized completely using a probe sonicator, and the amount of unloaded drug was determined by measuring the absorbance at a wavelength of 231 nm on a Tecan Infinite M Plex plate reader (Table 2). Percentage drug loading was calculated using Eq. 1 [18]:  % Drug Loading =

 Weight of drug in nanoparticles × 100 Weight of nanoparticles

(1)

Polymeric Lipid Nanoparticles for Donepezil Delivery

2.2.6

55

Release Studies

Blank and drug-loaded nanoparticles (L-CS and Ge-L NPs) were dried overnight in a vacuum desiccator. The samples (40 mg) were redispersed in a 5 mL of acetate buffer (pH 5.5) and incubated in a shaking incubator at 100 rpm. The release media (2 mL) was withdrawn from each sample at specified time points and replaced with the fresh media. The releasates were analyzed, and the amount of drug was quantified by measuring the absorbance at a wavelength of 231 nm using the plate reader. The percentage of cumulative drug release was plotted against time (h) and reported as an average value of triplicate measurements. The kinetics of drug release for both nanosystems were studied using the following four models: zero order, first order, Higuchi, and Korsmeyer-Peppas. The model with the highest R2 value was reported to be the best-fit model.

2.2.7

Cell Viability Studies

The cell viabilities of both nanosystems, with and without drug, were assessed on mouse fibroblast (L929) cell line using MTT assay. The cells were cultured in RPMI1640 media supplemented with FBS (5% v/v) and penicillin (1% v/v) in a culture flask (37 °C, 5% CO2 ) till 70% of cells were confluent [19]. Cells at a density of 1 × 105 /mL were seeded in tissue culture-treated 48 well plates and incubated for 24 h. The samples, L-CS NPs, donepezil-loaded L-CS NPs, Ge-L NPs, and donepezilloaded Ge-L NPs (1 mg/mL each), were incubated in media for 24 h at 37 °C and the conditioned media was filtered through a 0.22 μ syringe filter. The media of cells were replaced with the conditioned media and incubated for another 24 h. MTT solution (30 μL, 5 mg/mL) was added to the each well and incubated for 3.5 h at 37 °C. The formazan crystals formed were dissolved in DMSO (100 μL), and absorbance was recorded at 570 nm using a plate reader. The percent cell viability was estimated using the following Eq. 2 [20]:  % Cell Viability = 1 −

2.2.8

 Absorbancecontrol − Absorbancesample × 100 Absorbancecontrol

(2)

Mucoadhesion Studies

The mucoadhesive property of both polymeric lipid NPs, with and without drug, was evaluated with porcine stomach mucin (Type III) as it closely mimics the acidic nasal mucosa conditions. Briefly, mucin solution (0.5 mL, 5 mg/mL) was added to the nanoparticle suspension (0.5 mL) and incubated in a shaking incubator at 37 °C (100 rpm, 1.5 h) [21]. After incubation, the mixture was centrifuged at 10,000 rpm for 5 min, and the supernatant was collected. The amount of free mucin was quantified using the Bradford protein assay by measuring the absorbance at 595 nm.

56

M. Bhandari et al.

3 Results and Discussion 3.1 Fabrication and Characterization of L-CS and Ge-L Hybrid Nanosystems The lecithin chitosan nanoparticles (L-CS) were prepared from the soy lecithin and chitosan using the ionic gelation method, whereas the gelatin lecithin (Ge-L) nanoparticles were prepared from gelatin and soy lecithin using the desolvation method (Scheme 1). The FTIR spectrum for lecithin showed the characteristic peaks at 2854 and 2927.89 cm−1 corresponding to the C–H stretching of methylene group. A peak at 1737.68 cm−1 corresponded to the C=O stretching, and another at 1058.307 cm−1 corresponded to the P–O–C stretching (Fig. 1). For chitosan, the peak at 2877.49 cm−1 corresponded to the N–H stretching due to the presence of amine group, the peak of 1642.13 cm−1 corresponded to N–H bending due to the amine group, and the peak at 1062.82 cm−1 to C–O stretching [16, 19]. The FTIR spectrum of donepezil hydrochloride showed peaks at 1131.09, 1591.72, 2984.32, and 3629.84 cm−1 corresponding to C–O stretching, N–H bending, and broad and sharp O–H stretching. All peaks corresponding to chitosan and lecithin were also found in L-CS NPs and donepezil-loaded L-CS NPs along with the additional peaks at 3652 and 2917 cm−1 , which indicated the drug incorporation into NPs. Similar observations were made for gelatin and drug-loaded Ge-L nanoparticles (Fig. 2), where the peak at 3737 cm−1 indicated the encapsulation of drug into the nanoparticles. The particle size distribution of L-CS and Ge-L NPs is shown in Fig. 3. The nanosystems were diluted with a mixture of acetate buffer and methanol in the ratio of 4:1 to measure the particle size. All values are reported as an average value of 15 runs per sample with triplicate measurements for each sample [14]. The NPs prepared

Scheme 1 Fabrication of nanoparticles: a L-CS and b Ge-L

Polymeric Lipid Nanoparticles for Donepezil Delivery

57

Fig. 1 FTIR spectra: a Lecithin, b chitosan, c donepezil, and d L-CS NPs and donepezil-loaded L-CS NPs

Fig. 2 FTIR spectra: a Gelatin and b donepezil-loaded Ge-L NPs

with lecithin and chitosan in the ratio of 10:1 showed the polydispersity index (PDI) in the range of 0.02–0.16, thereby indicating a fairly uniform dispersion of particles. Similarly, the NPs prepared with gelatin and lecithin in the ratio of 20:1 also formed a monodisperse suspension of particles, as evident from their PDI values. The L-CS and Ge-L NP solutions used for zeta potential (ZP) measurement were similar to the ones used for the measurement of particle size, and the potential values were reported as an average of triplicate measurements taken for each sample (Table

58

M. Bhandari et al.

Fig. 3 Particle size distribution of nanoparticles: a Ge-L and b L-CS

Table 1 Average particle size, PDI, and ZP (n = 3, mean ± standard deviation) S. No.

Sample

Average size (nm)

PDI

1

L-CS NPs

237.43 ± 44.49

0.080 ± 0.059

1.167 ± 0.41

2

Ge-L NPs

278.86 ± 92.38

0.090 ± 0.060

−5.53 ± 0.094

Table 2 Donepezil (drug) loading efficiencies of L-CS and Ge-L NPs

Zeta potential (mV)

S. No.

Sample

D4 (4 mg/mL)

D8 (8 mg/mL)

1

L-CS NPs

0.53 ± 0.147%

10.24 ± 0.432%

2

Ge-L NPs

8.77 ± 0.748%

0.46 ± 0.158%

1). The net surface charge observed on L-CS nanoparticles was positive due to the presence of amine groups in chitosan, whereas the net surface charge observed on Ge-L nanoparticles was negative due to the presence of hydroxyl groups. The LCS NPs owing to their positive surface charge are likely to penetrate through the negatively charged nasal mucosa [16]. The SEM images revealed rigid shells with a nearly spherical shape of lecithin chitosan, and the particles were seen in aggregated form, whereas the gelatin lecithin NPs showed distorted morphology with huge aggregation and lipid-like structure [22] (Fig. 4).

3.2 Drug Loading and Release The donepezil loading for L-CS and Ge-L NPs was estimated, as shown in Table 2. The release of donepezil from drug-loaded L-CS NPs was studied in an acetate buffer of pH 5.5 to mimic the nasal mucosa pH of 4.5–6.5 (Fig. 5) [9, 17]. The percentage cumulative drug release was observed over a period of 5 days, and up to 99.99 ± 0.0343% of drug was found to be released (mean ± SD). The release of

Polymeric Lipid Nanoparticles for Donepezil Delivery

59

Fig. 4 SEM images of nanoparticles: a L-CS (scale bar: 2 µm) and b Ge-L (scale bar: 1 μm)

Fig. 5 Drug (donepezil) release studies (n = 3, mean ± SD): a L-CS NPs and b Ge-L NPs

drug from Ge-L NPs, in similar acidic conditions, was observed for 45 days. The average percentage cumulative drug release was estimated as 36.33%. The kinetics of donepezil release from the drug-loaded L-CS NPs were studied with different models: zero order, first order, Higuchi, and Korsmeyer-Peppas (Fig. 6), and the average R2 values were found to be 0.8113, 0.5158, 0.954, and 0.8508. The highest value of R2 was obtained for the Higuchi model, indicating that the drug release from the L-CS NPs followed the Higuchi kinetics, which implies that the initial drug loading in the system exceeds its solubility for the same system and the concentration of dissolved drug in the system remains constant throughout most of the drug delivery. Similarly, the R2 values for the drug-loaded Ge-L NPs (Fig. 7) were found to be 0.837, 0.586, 0.960, and 0.929. The highest R2 value was observed for the Higuchi model, indicating a diffusion-based sustained release kinetics.

60

M. Bhandari et al.

Fig. 6 Drug release kinetics in L-CS NPs (n = 3, mean ± SD)

Fig. 7 Drug release kinetics in Ge-L NPs (n = 3, mean ± SD)

3.3 Cell Viability Studies To confirm that the nanoparticulate systems were safe in nature, a MTT assay was performed on L929 cell line. All samples showed more than 80% of cell viability

Polymeric Lipid Nanoparticles for Donepezil Delivery

61

Fig. 8 Cell viability studies using L929 cell line (mean ± SD, n = 3). D denotes the drug

and, thus, can be regarded as safe in nature (Fig. 8). As expected, blank nanoparticles were having higher cell viability as compared to drug-loaded nanoparticles owing to the obvious toxic nature of drug.

3.4 Mucoadhesion Studies For an efficient intranasal delivery, mucoadhesive characteristics are required. The mucoadhesive properties of L-CS and Ge-L (both unloaded and loaded) NPs on porcine stomach mucin (Type III) were determined by Bradford assay (Fig. 9) [16, 21]. Both chitosan and gelatin were found to be mucoadhesive in nature, and the donepezil-loaded NPs were only slightly less mucoadhesive than unloaded NPs, owing to the hindrance caused by the presence of drug. Fig. 9 Mucoadhesion studies (mean ± SD, n = 2). D denotes the drug

62

M. Bhandari et al.

4 Conclusions In summary, we have fabricated and characterized two nanoparticulate systems, lecithin chitosan (L-CS) and gelatin lecithin (Ge-L), from naturally occurring polymers, such as gelatin, chitosan, and lecithin, for the intranasal controlled/sustained delivery of donepezil, an acetylcholinesterase inhibitor used in the management of Alzheimer’s disease (AD). Both nanoparticulate systems were found non-toxic against murine fibroblasts cell line and showed good mucoadhesion on porcine stomach mucin (Type III), which is known to mimic the acidic conditions of nasal mucosa. Therefore, the nanoparticulate systems can be used for the intranasal donepezil delivery. The drug release studies at acidic pH revealed distinct differences between the two systems: the drug-loaded L-CS NPs showed a burst release, and most of the drug was released quickly, whereas the drug-loaded Ge-L NPs provided the sustained release for a longer duration. Thus, Ge-L NPs formed stable nanodispersion and showed the sustained release kinetics, and it can be further evaluated in an animal model to establish its efficacy. Acknowledgements Financial assistance from the DBT India to Y.S. (BT/PR40669/MED/32/761/2020) is gratefully acknowledged. We also thank the Departments of Biomedical Engineering and Chemistry for providing the access to their research facilities. M.B. and N.R. received their fellowships from IIT Ropar.

References 1. Nisbet RM, Götz J (2018) Amyloid-β and Tau in Alzheimer’s disease: novel pathomechanisms and non-pharmacological treatment strategies. J Alzheimers Dis 64(s1):S517–S527. https:// doi.org/10.3233/JAD-179907 2. (2020) Alzheimer’s disease facts and figures. Alzheimer’s Dement 16(3):391–460 3. NIH National Institute on Aging. https://www.nia.nih.gov 4. Jelic V, Darreh-Shori T (2010) Donepezil: a review of pharmacological characteristics and role in the management of Alzheimer disease. Clin Med Insights: Ther 2:771–788. https://doi.org/ 10.4137/CMT.S5410 5. Devnarain N, Ramharack P, Soliman ME (2017) Brain grants permission of access to Zika virus but denies entry to drugs: a molecular modeling perspective to infiltrate the boundary. RSC Adv 7(75):47416–47424. https://doi.org/10.1039/C7RA05918C 6. Liew KB, Tan YTF, Peh KK (2012) Characterization of oral disintegrating film containing donepezil for Alzheimer disease. AAPS PharmSciTech 13(1):134–142. https://doi.org/10. 1208/s12249-011-9729-4 7. Fonseca LC, Lopes JA, Vieira J et al (2021) Intranasal drug delivery for treatment of Alzheimer’s disease. Drug Deliv Transl Res 11(2):411–425. https://doi.org/10.1007/s13346-021-00940-7 8. Pires PC, Santos AO (2018) Nanosystems in nose-to-brain drug delivery: a review of nonclinical brain targeting studies. J Control Release 270:89–100. https://doi.org/10.1016/j.jco nrel.2017.11.047 9. Yousfan A, Rubio N, Natouf AH et al (2020) Preparation and characterization of PHTloaded chitosan lecithin nanoparticles for intranasal drug delivery to the brain. RSC Adv 10(48):28992–29009. https://doi.org/10.1039/D0RA04890A

Polymeric Lipid Nanoparticles for Donepezil Delivery

63

10. Elzoghby AO (2013) Gelatin-based nanoparticles as drug and gene delivery systems: reviewing three decades of research. J Control Release 172(3):1075–1091. https://doi.org/10.1016/j.jco nrel.2013.09.019 11. Kommareddy S, Shenoy DB, Amiji MM (2007) Gelatin nanoparticles and their biofunctionalization. Nanotechnologies Life Sci. https://doi.org/10.1002/9783527610419.ntls0011 12. Abbasiliasi S, Shun TJ, Tengku Ibrahim TA et al (2019) Use of sodium alginate in the preparation of gelatin-based hard capsule shells and their evaluation: in vitro. RSC Adv 9(28):16147–16157. https://doi.org/10.1039/C9RA01791G 13. Hafner A, Lovri´c J, Pepi´c I, Filipovi´c-Grˇci´c J (2011) Lecithin/chitosan nanoparticles for transdermal delivery of melatonin. J Microencapsul 28(8):807–815. https://doi.org/10.3109/026 52048.2011.622053 14. Chhonker YS, Prasad YD, Chandasana H et al (2015) Amphotericin-B entrapped lecithin/chitosan nanoparticles for prolonged ocular application. Int J Biol Macromol 72:1451– 1458. https://doi.org/10.1016/j.ijbiomac.2014.10.014 15. Pineda-Álvarez RA, Bernad-Bernad MJ, Rodríguez-Cruz IM et al (2020) Development and characterization of starch/gelatin microneedle arrays loaded with lecithin-gelatin nanoparticles of losartan for transdermal delivery. J Pharm Innov. https://doi.org/10.1007/s12247-020-094 94-6 16. Jain S, Valvi PU, Swarnakar NK, Thanki K (2012) Gelatin coated hybrid lipid nanoparticles for oral delivery of Amphotericin B. Mol Pharm 9(9):2542–2553. https://doi.org/10.1021/mp3 00320d 17. Zhang L, Chan JM, Gu FX et al (2008) Self-assembled lipid-polymer hybrid nanoparticles: a robust drug delivery platform. ACS Nano 2(8):1696–1702. https://doi.org/10.1021/nn800275r 18. Gajendiran M, Jainuddin Yousuf SM, Elangovan V, Balasubramanian S (2014) Gold nanoparticle conjugated PLGA-PEG-SA-PEG-PLGA multiblock copolymer nanoparticles: synthesis, characterization, in vivo release of rifampicin. J Mater Chem B, Mater Biol Med 2(4):418–427. https://doi.org/10.1039/C3TB21113D 19. Perez-Ruiz AG, Ganem A, Olivares-Corichi IM, García-Sánchez JR (2018) Lecithin-chitosanTPGS nanoparticles as nanocarriers of (-)-epicatechin enhanced its anticancer activity in breast cancer cells. RSC Adv 8(61):34773–34782. https://doi.org/10.1021/nn800275r 20. Foo JB, Ng LS, Lim JH, Tan PX, Lor YZ, Loo JSE, Low ML, Chan LC, Beh CY, Leong SW, Saiful Yazan L, Tor YS, How CW (2019) Induction of cell cycle arrest and apoptosis by copper complex Cu(SBCM)2 towards oestrogen-receptor positive MCF-7 breast cancer cells. RSC Adv 9(32):18359–18370. https://doi.org/10.1039/C9RA03130H 21. Lee JS, Suh JW, Kim ES, Lee HG (2017) Preparation and characterization of mucoadhesive nanoparticles for enhancing cellular uptake of coenzyme Q10. J Agric Food Chem 65(40):8930–8937. https://doi.org/10.1021/acs.jafc.7b03300 22. Gonçalves VSS, Poejo J, Matias AA, Rodríguez-Rojo S, Cocero MJ, Duarte CMM (2016) Using different natural origin carriers for development of epigallocatechin gallate (EGCG) solid formulations with improved antioxidant activity by PGSS-drying. RSC Adv 6(72):67599– 67609. https://doi.org/10.1039/C6RA13499H

Role of Natural Polymers as Carriers for Targeting Cognitive Disorder Bhavna , Arpita Sahoo, and Manmohan Singhal

1 Introduction Cognitive disorders can be categorized under mental health disorders (Fig. 1). Cognitive disorders include dementia, amnesia and delirium. First and foremost, the cognitive disorders affect the memory, learning, problem solving and perception in an individual person. Hence, cognitive disorder’s diagnosis can be temporary or progressive, which depends upon the cause [1, 2]. Biopolymers are the biological polymers or natural polymers derived from natural sources or synthesized artificially. Natural biodegradable polymers are extensively used in drug delivery because of their lower toxicity, biocompatibility, biodegradability, and it is abundantly present in nature. Natural biodegradable polymers are protein-based polymers, for example: gelatin, collagen, soy, albumin, and polysaccharides, for example: pullulan, chitosan, agarose, dextran, hyaluronic acid, carrageenan and cyclodextrin, etc. [3, 4]. Pullulan attracts the attention of researchers due to its nature of nontoxic, nonmutagenic, which is readily absorbed in both water and dilute alkali because it is non-hygroscopic. This is a neutral polymer derived from the yeast like fungus known as Aureobasidium pullalans. Pullulan is an aqueous polysaccharide that comprises of hundreds of repeated units of the maltotriose trimer α-d-glucopyranosyl-(1 → 6)-αd-glucopyranosyl-(1 → 4)-α-d-glucopyranosyl-(1 → 4) [5]. Pullulan is proved to be an exceptional carrier for therapeutic molecules that it directly targets to several organs of the body as brain, spleen, lungs, liver, etc. Therefore, it releases very particular cytotoxic molecules to the specific infected site [6, 7]. Vildagliptin is a novel oral hypoglycaemic agent that is freely soluble in water. The oral bioavailability of vildagliptin is of 85%, and it has a protective effect on cardiovascular system and pancreas. As per the existing literature with respect to Bhavna (B) · A. Sahoo · M. Singhal Faculty of Pharmacy, DIT University, Dehradun, Uttarakhand 248009, India e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_6

65

66

Bhavna et al.

Fig. 1 Classification of categories of cognitive disorders

cognitive disorder, treatment with vildagliptin results in the decrease in neuronal apoptosis in the hippocampus, and it also improves memory deficit. Vildagliptin improves memory impairment and spatial learning in the cognitive disorder patients. Treatment with vildagliptin exerted significant protection against cognitive disorderinduced neurotoxicity and also enhances the expressions of the proteins associated with synaptic plasticity [8]. Polymeric nanomicelles are the structures formed by amphiphilic block copolymers and made up of nanoscopic shell/core structures [9]. Polymeric nanomicelles size is generally of 10–200 nm having unique properties of high stability, biodegradability, reduced size and low CMC [10]. Additionally, polymeric nanomicelles have very distinctive properties including longer blood circulation time, drug payload, biocompatibility and relative stability [11]. In the present study, the authors are targeting neurodegeneration by use of a pullulan for encapsulating the drug (vildagliptin) and prepare the polymeric nanomicelles, which can be delivered by nasal route to target the brain. As the drug shows a flip-flop phenomenon which signifies a the rate of absorption of drug is slower than the rate of elimination. The pullulan-based nanoformulation showed remarkably a better candidate for improved absorption and high bioavailability at the target site in brain on the basis of characterization of in vitro and in vivo analysis.

2 Materials and Method 2.1 Materials Vildagliptin API was received as a gift sample from Glenmark Pharmaceuticals, Mumbai, India. Polymer (pullulan) was purchased from Sigma Aldrich, New Delhi, India, The Surfactant (tween 80 was of analytical grade purchased from SD fines,

Role of Natural Polymers as Carriers for Targeting Cognitive …

67

Table 1 Formulation of drug loaded PNMs Formula

Formulation of drug loaded PNMs

Solvent (water)

Drug(mg)

Polymer(mg)

Tween 80(ml)

(ml)

V1

0.5

0.5

0.2

20

V2

0.5

1.0

0.2

20

V3

0.5

1.5

0.2

20

V4

0.5

2.0

0.2

20

New Delhi, India. All other chemicals and reagents used are of analytical grade without further purification.

2.2 Method for Preparation of Polymeric Nanomicelles (PNMs) Loaded with Drug Drug loaded PMNs were fabricated using the simple direct dissolution method [12]. Briefly, various concentration of pullulan polymers was made in the solvents and stirred on magnetic stirrer at for 1500 rpm for 20 min. The range of polymers was from 0.5, 1.0, 1.5, 2.0, with a constant drug concentration of 0.5% as mentioned in Table 1. The resultant polymeric nanomicelles were centrifuged at 6000 rpm for 20 min (REMI R-24), followed by filtration of the surfactant using a 0.2-μm cellulose acetate membrane filter (Chemtech International, Gujarat, India) to remove the incorporated drug aggregates. The prepared polymeric nanomicelles were characterized for practice shape, size, zeta potential, drug loading and drug entrapment efficiency and in vitro release.

3 Characterization For Drug Loaded PNMS 3.1 Particle Shape and Particle Size with Zeta Potential The shape of drug loaded PNMs was identified by Field Emission Scanning Electron Microscopy (FESEM) which works with electron instead of light. The object is scanned by electron in a zig-zag pattern. It has a very advanced image quality [13]. Polymeric nanomicelles particle size was confirmed using Malvern Zetasizer (Nanozydus Malvern Zetasizer, UK). After the appropriate dilution, all the measurements were performed in the triplicate manner by using deionized (DI) water. Both the PDI and particle size were measured before and after lyophilisation [12].

68

Bhavna et al.

3.2 Encapsulation Efficiency and Drug Loading for Drug Loaded Polymeric Nanomicelles Drug loading (DL) is also known as loading capacity. To evaluate the suitability of the excipients, entrapment efficiency (EE) should be carried out; EE and DL can be calculated as mentioned in Eqs. (1) and (2) [14]: Percentage Encapsulation Efficiency(% EE) =

Weight of drug in the polymeric nanomicelles × 100 Weight of initial amount of drug

Weight of drug in the polymeric nanomicelles × 100 Percentage Drug Loading(% DL) = Weight of polymeric nanomicelles taken

(1) (2)

In the case of lipophilic compounds, the amount of drug in the micelles can be determined by HPLC analysis or spectrophotometrically after the separation of the undissolved drug. In the case of hydrophilic molecule the amount of drug encapsulated and free drug compound can be obtained by ultrafiltration spin column.

3.3 Fourier Transform Infrared Spectroscopy (FTIR) Vildagliptin and drug loaded PNMs were analysed for spectral peak determination by FTIR using Shimadzu spectrophotometer (Shimadzu, Kyoto, Japan). In this case, KBr pellet method was used, and each of the KBr disc was scanned under FTIR spectroscopy. The presence of characteristic peaks for samples was recorded and reported.

3.4 In Vitro Drug Release The release studies were performed for drug loaded PNMs. The in vitro release studies were carried out in the phosphate buffer media of 7.4 pH, using cellulose membrane, dialysis bag (molecular weight is 12,000 Dalton, flat weight with 25 mm and diameter of 16 mm) purchased from (Sigma Aldrich Chemicals Pvt Ltd., St. Louis, MO). The drug loaded nanoformulation samples were enclosed in dialysis bag and incubated in 100 ml phosphate buffer with shaking on water bath with 37 °C. Samples (5 ml) were withdrawn at a predetermined time interval and analysed at a wavelength 210 nm using UV spectrophotometer (Shimadzu, Japan).

Role of Natural Polymers as Carriers for Targeting Cognitive …

69

3.5 In Vivo Release Studies—Morris Water Maze Test Protocol Morris Water Maze test specifically is the test of spatial memory [15]. The hippocampus located in the temporal lobe of the brain is specifically involved in spatial/ relational memory [16, 17]. Morris water maze setup must have a round pool which is about 3 feet deep and 6 feet in diameter. The setup is filled with tap water, and 26 °C temperature is maintained. The water is made opaque with the use of non-toxic paint on the walls of the tank. Each animal will go through 12 trials, and it will last for 60 s. The animal handler will place the animal in the water, facing to the wall of the pool. Then the animal will perform the maze test. SMART system (San Diego Instruments) is a kind of animal behaviour tracking system that is used to monitor the path as well as the other variables. Monitor and record the time for each animal until it reaches the respective platform. The testing order should be trial1, trial 2, trial 3, etc. for all the animals. While performing this study, there must be an inter-trial interval for about 2 min [18]. One probe trial will be performed, when all the animals have completed 12 trials, and from this, the platform is removed out from the pool. To verify the strategy and understanding of the animals, when they discover that the platform is not there, the probe trial is performed. Starting from the north, the handler will release the animal. Finally, record the number of times for 30 s in which the animal crosses the centre of the pool [18].

3.6 Stability Studies Polymeric nanomicelles stability can be of thermodynamic and kinetic stability. The kinetic stability designates the rate of nanomicelles dis-assembly and polymer exchange and also the behaviour of the scheme over the period of time, while thermodynamic stability defines the system that acts as micelles which are designed and reach to the equilibrium [19]. After the preparation of the vildagliptin loaded nanomicelles based on the optimized formulation, until the instability was observed at room temperature of 25 °C, the prepared formulation was observed over a period of 3 months at 4 °C. Samples were withdrawn at regular interval of 0, 30, 60 and 90 days. It is further then evaluated for the sedimentation behaviour, analytical measurement and visual clarity of the drug degradation.

70

Bhavna et al.

4 Results and Discussions 4.1 Particle Shape and Particle Size with Zeta Potential In the recent work, drug (vildagliptin) loaded PNMs was made using direct dissolution method. The particle shape was analysed by FESEM showing spherical shape for optimized drug loaded as mentioned in Fig. 2. The average particle size and zeta potential of polymeric nanomicelles were measured by zetasizer [20] (Zetasizer— ZEN 3600 Malvern Instrument Ltd). The particle size diameter of the polymeric nanomicelles formulation was found to have 281.9 nm as represented in Fig. 3a. The particle stability is represented by zeta potential which is a measure of charge of the particles; the larger the absolute value of the zeta potential, the larger the amount of charge of the surface [21, 22]. The mean zeta potential of drug loaded pullulan nanomicelles was −6.94 V as given in Fig. 3b, showing stability of the prepared formulation.

4.2 Fourier Transform Infrared Spectroscopy The spectrum of FTIR analysis revealed that pure drug has distinctive peaks of 1713.5, 3314.3 and 3367.5 per cm. The urea carbonyls stretching was observed at 1618.4, 1526.5 per cm and SO2 stretching vibration showed at 1158 and 1341.5 as shown in Fig. 4a and b. No new bonds will be observed which confirm no new chemical bonds form between drug and polymer as given in Fig. 4a and b. Fig. 2 Particle shape by FESEM for optimized drug loaded PNMs

Role of Natural Polymers as Carriers for Targeting Cognitive …

Fig. 3 Particle size a and Zeta potential b for drug loaded PNMs

Fig. 4 FTIR of a drug loaded PNMs, b plain drug

71

72

Bhavna et al.

Fig. 5 Comparative drug release profile for plain drug and drug loaded nanoparticle

4.3 Encapsulation Efficiency (EE) and Drug Loading (DL) for Optimized Drug Loaded PNM In order to achieve higher drug loads, the EE and DL of drug loaded PNMs are important so as to evaluate the efficiency of different preparation methods of nanomicelles. The EE and DL of optimized drug loaded PNMs were found to be 91.15 ± 04% and 62.21 ± 05%, respectively.

4.4 Drug Release Studies 4.4.1

In Vitro Release

The optimized drug loaded PNMs showed 83.78 ± 0.56% of release for 24 h in a controlled manner, compared with plain drug which shows maximum release in 16–18 h, as shown in Fig. 5. The data acquired from in vitro studies were built-in for several kinetic models such as zero-order, first-order, Higuchi and KorsemeyerPeppas model, to interpret the mechanism of drug.

4.4.2

In Vivo Behavioural Study

Morris Water Maze test was used to evaluate in vivo behavioural activity of optimized nanoformulation in mice. For spatial learning for rodents, Morris Water Maze is performed [23]. Morris Water Maze test is a possibly a powerful experimental

Role of Natural Polymers as Carriers for Targeting Cognitive …

73

Fig.6 Graphical representation of the drug loaded nanomicellar formulations

method for examining the environmental factor, influence of genes and their interactions on the development of learning and memory [24]. Optimized polymeric nanomicelles were found to be effective in mice model for behavioural studies. Polymeric nanomicelles of vildagliptin reduces the escape latency in Morris Water Maze task which showed their positive effect on learning and memory as shown in Fig. 6. However, V2 formulation containing 1 mg of polymer (pullulan) exhibits optimum efficacy. Polymer concentration less than or more than 1 mg significantly reduced the efficacy. So, our result showed that polymeric nanomicelles of vildagliptin containing 1 mg of pullulan may produce optimum drug delivery to target site for management of dementia and Alzheimer’s disease.

4.5 Stability Studies The statistical analysis of the optimized samples of polymeric nanomicelles was used for student’s t-test, and p-value < 0.5 was considered statistically significant. All the reported data showed mean ± standard deviation unless otherwise noted.

5 Conclusion In the recent work, drug (vildagliptin) loaded PNMs were effectively and successfully established, which is prepared using drug and tween 80. The amount of tween 80 is kept constant throughout the preparation method; it has a potential surfactant like property which helps to increase the nanomicellar association with the target cells. Natural polymer like pullulan has an extraordinary property like non-mutagenic and

74

Bhavna et al.

non-toxic; it is proved to be an exceptional carrier for therapeutic molecules that it can directly targets to the organs like brain, lung, spleen, liver, etc. The present study revealed V2 as the best optimized polymeric nanomicelles with use of pullalan and tween 80. All the characteristic analysis was done for the optimized PNMs whether it is particle shape, particle size or particle stability using zeta potential determination. The drug loading, encapsulation efficiency, in vitro drug release and stability studies were finally performed. Hence, it was concluded that polymeric nanomicellar formulation approach can be beneficial to target the brain to improve cognitive disorders and can be a suitable approach for other delivery systems as nasal delivery for targeting brain.

References 1. Zuckerman H, Pan Z, Park C, Brietzke E, Musial N, Shariq AS, Iacobucci M, Yim SJ, Lui LMW, Rong C, McIntyre RS (2018) Recognition and treatment of cognitive dysfunction in major depressive disorder. Front Psychiatry 9:655. https://doi.org/10.3389/fpsyt.2018.00655 2. McWhirter L, Ritchie C, Stone J, Carson A (2020) Functional cognitive disorders: a systematic review 7(2):191–207.https://doi.org/10.1016/S2215-0366(19)30405-5 3. Joyce K, Fabra GT, Bozkurt Y, Pandit A (2021) Bioactive potential of natural biomaterials: identification, retention and assessment of biological properties. Signal Transduct Target Ther 6(1):122. https://doi.org/10.1038/s41392-021-00512-8 4. Caillol S (2021) Special Issue “Natural Polymers and Biopolymers II”. Molecules 26(1):112. https://doi.org/10.3390/molecules26010112 5. Zhang T, Yang R, Yang S, Guan J, Zhang D, Ma Y, Liu H (2018) Research progress of selfassembled nanogel and hybrid hydrogel systems based on pullulan derivatives. Drug Delivery 25:278–292. https://doi.org/10.1080/10717544.2018.1425776 6. Gupta M, Gupta AK (2004) Hydrogel pullulan nanoparticles encapsulating pBUDLacZ plasmid as an efficient gene delivery carrier. J Control Release 99(1):157–166. https://doi.org/10.1016/ j.jconrel.2004.06.016 7. Singh RS, Saini GK (2014) Pullulan as therapeutic tool in biomedical applications. Book: advances in industrial biotechnology 2014. Publisher, I. K. International Publishing House Pvt. Ltd, pp 263–291 8. Ma QH, Jiang LF, Mao JL, Xu WX, Huan M (2017) Vildagliptin prevents cognitive deficits and neuronal apoptosis in a rat model of Alzheimer’s disease. Spandidos Publication, Molecular Medicine Report 17:4113–4119. https://doi.org/10.3892/mmr.2017.8289 9. Croy SR, Kwon GS (2006) Polymeric micelles for drug delivery. Curr Pharm Des 12(36):4669– 4684. https://doi.org/10.2174/138161206779026245 10. Sharma D, Kumar B (2019) Formulation and evaluation of polymeric nanomicelles of gliptin for controlled drug delivery. Drug Deliv Lett 9(2):146–156. https://doi.org/10.2174/221030 3109666190212112505 11. Shajari M, Rostamizadeh K, Shapouri R, Taghavi L (2020) Eco-friendly curcumin-loaded nanostructured lipid carrier as an efficient antibacterial for hospital wastewater treatment. Environ Technol Innov 18:1–16. https://doi.org/10.1016/j.eti.2020.100703 12. Mahmood S, Mandal UK, Chatterjee B, Taher M (2016) Advanced characterizations of nanoparticles for drug delivery: investigating their properties through the techniques used in their evaluations. 6(4):355–372. https://doi.org/10.1515/ntrev-2016-0050 13. Jafarieh O, Muhammad S, Ali M, Baboota S, Sahni JK, Kumari B, Bhatnagar A, Ali J (2015) Design, characterization, and evaluation of intranasal delivery of ropinirole-loaded mucoadhesive nanoparticles for brain targeting. Drug Dev Ind Pharm 41(10):1674–1681. https://doi. org/10.3109/03639045.2014.991400

Role of Natural Polymers as Carriers for Targeting Cognitive …

75

14. Shen SH, Wu YS, Liu YC, Wu DC (2017) High drug-loading nanomedicines: progress, current status, and prospects. Int J Nanomed 12:4085–4109. https://doi.org/10.2147/IJN.S132780 15. D’Hooge R, De Deyn PP (2001) Applications of the Morris water maze in the study of learning and memory. Brain Res 36(1):60–90. https://doi.org/10.1016/s0165-0173(01)00067-4 16. Kesner RP, Exans RB, Hunt MA (1987) Further evidence in support of the neurobiological bases of an attribute model of memory:role of the hippocampus. Int J Neurosci 1987–8(21–22):21–22 17. Jarrard LE, Okaichi H, Steward O, Goldschmidt RB (1984) On the role of hippocampal connections in the performance of place and cue tasks: comparisons with damage to the hippocampus. Behav Neurosci 98:946–954. https://doi.org/10.1037//0735-7044.98.6.946 18. Nunez J (2008) Morris water maze experiment. JoVE J 19:897. https://doi.org/10.3791/897 19. Shawn CO, Dianna PYC, Molly SS (2012) Polymeric micelle stability. Nano Today 7:53–65. https://doi.org/10.1016/j.nantod.2012.01.002 20. Lamoudi L, Chaumeil JC, Daoud K (2013) PLGA nanoparticles loaded with the non-steroid anti-inflammatory: factor influence study and optimization using factorial design. IJCEA 4(6):369–372. https://doi.org/10.7763/IJCEA.2013.V4.327 21. HansA ML, Lowman M (2002) Biodegradable nanoparticles for drug delivery and targeting. Curr Opin Solid State Mater Sci 6(4):319–327. https://doi.org/10.1016/S1359-0286(02)001 17-1 22. Micheli J, Luana C, Ferreira M, Gomes FP, De C, Da B, Leandro S, Cruz TL (2016) Pullulan as a stabilizer agent of polymeric nanocapsules for drug delivery. Braz J Pharm Sci 52(4):735–740. https://doi.org/10.1590/S1984-82502016000400018 23. Vorhees CV, Williams MT (2006) Morris water maze: procedures for assessing spatial and related forms of learning and memory. Nat Protoc 1(2):848–858. https://doi.org/10.1038/nprot. 2006.116 24. Barnhart CD, Yang D, Lein PJ (2015) Using the morris water maze to assess spatial learning and memory in weanling mice. Plos org 10(4):e0124521.https://doi.org/10.1371/journal.pone. 0124521

Copper(II)-Catalyzed Ring Opening Polymerization of Cyclic Esters Isha Jain and Payal Malik

1 Introduction Biodegradable polyesters have emerged as a sustainable alternative to traditional petroleum-based non-biodegradable polymers [1–3]. These polyesters have diverse applications in drug and gene delivery systems, bioengineering, packaging and bioadhesive industries [4–7]. In the recent past, low-molecular weight polyesters have received attention in the medical field due to their biocompatibility and bioresorability [8]. Ring opening polymerization (ROP) of cyclic esters such as -caprolactone (CL), δ-valerolactone (VL), lactide (LA) and β-butyrolactone (BL) is one of the promising methods which enable access to polyesters of desired molecular weights (M n ). Commonly, ROP is carried out in presence of catalysts, in this regard, organometallic catalysts are unarguably the most effective catalysts for ROP of cyclic esters [9–11]. However, associated metal contamination in the resultant polymers restricts their applications in the pharmaceutical industry. Thus, the use of non-toxic metal-based catalysts for the synthesis of polyesters is the need of the hour. In addition to non-toxic catalysts, mild reaction conditions are also desirable for industrial-scale processes where energy conservation is important from the cost and environmental point of view. Various rare earth metals [12, 13], aluminium [14–16], zinc [17], bismuth [18, 19], tin [20], yttrium [21] and iron [22–24] salts have been used as catalysts for ROP of cyclic esters. In addition, tin and aluminium catalysts have been used for the synthesis of hyperbranched polyesters in the presence of multifunctional initiators [25–27]. However, only a limited number of metal salts have been reported to date for the synthesis of hyperbranched polyesters [28–33]. Since poly(caprolactone) (PCL) and poly(valerolactone) (PVL) have numerous applications in the biomedical field so the use of environmentally benign catalysts I. Jain · P. Malik (B) Department of Chemistry, Sant Longowal Institute of Engineering and Technology, Longowal, Sangrur, Punjab 148106, India e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_8

77

78

I. Jain and P. Malik

is of utmost importance. In the quest of synthesizing linear and hyperbranched biodegradable polyesters using an environment-friendly catalyst, we investigated the catalytic efficiency of commercially available Cu(ClO4 )2 ·6H2 O towards ROP of CL and VL under ambient conditions using different initiators.

2 Materials Copper perchlorate hexahydrate (Cu(ClO4 )2 ·6H2 O), and all the alcohols, i.e. benzyl alcohol (BnOH), propargyl alcohol, 1,5-pentadiol, pentaerythritol and dipentaerythritol were purchased from Sigma Aldrich. CL and VL were purchased from Sigma Aldrich, dried over CaH2 and used freshly distilled. Toluene and tetrahydrofuran (THF), purchased from RANKEM, were distilled over sodium prior to use. 1 H NMR measurements were performed on Bruker Avance 400 MHz spectrometer. Chemical shifts are reported in parts per million (ppm) and referenced to residual solvent resonances. Differential scanning calorimeter (DSC) was recorded on STA 449 F3 Jupiter at heating rate 10 k/min in presence of N2 . GPC was performed with Waters 510 pump and Waters 410 Differential Refractometer as the detector. Columns STRYGEL-HR5, STRYGEL-HR4 and STRYGEL-HR3 were connected in series. M n and molecular weight distribution (MWD) were measured using THF at 27 °C relative to polystyrene standards.

3 Experimental Methods 3.1 General Procedure for Ring Opening Polymerization of CL and VL All the polymerization reactions were performed under N2 atmosphere at room temperature. The polymerization flask was flushed with N2 and then added CL (200 equiv.) and Cu(ClO4 )2 ·6H2 O (1 equiv.) followed by initiator (1 equiv.). The reaction mixture was stirred at room temperature till the stirring ceased at high speed (at rpm 2070). The contents were dissolved in dichloromethane and precipitated from cold n-pentane; the resultant products were dried under vacuum. Caution: Perchlorates are explosive and should be handled with care. However, during these reactions, we did not face any problems.

Copper(II)-Catalyzed Ring Opening Polymerization of Cyclic Esters

79

4 Results and Discussion Biodegradable polyesters have a number of applications in regenerative medicines, commodity products and agriculture. The aim of this study was to synthesize biodegradable polyesters using non-toxic, economical and commercially available catalyst under ambient conditions. Initially, the polymerization reaction was performed at room temperature maintaining [CL]:[cat] ratio 200:1 under solvent-free conditions, 94% conversion was achieved in 7 h (Entry 1). Subsequently, the activity of Cu(ClO4 )2 ·6H2 O was evaluated for ROP of CL in presence of different initiators (init.) enlisted in Fig. 1. With BnOH, polymerization was performed maintaining [CL]:[cat]:[initiator] ratio 200:1:1, PCL with M n = 5.9 kg/mol and with molecular weight distributions 1.08 was produced within 4 h (Entry 2). The observed M n of PCL was lower than the theoretical M n, ; this can be attributed to slow propagation rates. Further increase in BnOH concentration accelerates the polymerization reaction; in the case of 200:1:5 [CL]:[cat]:[BnOH], polymerization completed within 2.5 h but a decrease in M n was observed (Entry 3). Moreover, the effect of increased monomer concentration on the reaction was evaluated using ratio 500:1:1 of [CL]:[cat]:[BnOH]; monomer conversion was as high as 98%(Entry 4), which confirms the living nature of polymerization. The resultant PCL was characterized by 1 H NMR spectroscopy; the peaks at 4.00 and 3.8 ppm are assigned to -CH2 O of polymeric and terminal chains, respectively (see Fig. 2). The peaks at 5.2 and 7.2 ppm support the incorporation of BnOH in the polymeric chain. Subsequently, the effect of solvent on the polymerization was investigated by performing polymerization reactions in different solvents, namely toluene, THF and dichloromethane. The polymerizations were found to be slow in solvent. In addition, hyperbranched PCL were obtained using pentaerythritol and dipentaerythritol. Pentaerythritol produced PCL with M n = 5.7 kg/mol and MWD 1.12 in 7 h (Entry 7). The absence of –OH signals in 1 H NMR confirms the formation of hyperbranched polymer (see Fig. 3). Thermal analysis results also support the same as a slight increase in T m of PCL was observed (see Fig. 4). In case of pentaerythritol and dipentaerythritol initiated polymerizations, low monomer conversions

Fig. 1 Various initiators used in ROP of CL and VL.

1.3864

1.6497

4.0636

2.3111

I. Jain and P. Malik 7.2973

80

f+h+f’+h’

e+e’

i

g+g’

9

8

7

6

5

4

2.05

2.00

10

4.17

i’

d

3

2

2.17

a+b+c

1

0

ppm

Fig. 2 1 H NMR of Cu(ClO4 )2 ·6H2 O-catalyzed ROP of CL using BnOH as initiator maintaining [CL]:[cat]:[BnOH] ratio 500:1:1 (in CDCl3 )

were achieved due to their poor solubility in CL. To overcome this limitation, the reaction was performed at 80 °C in presence of Et3 N; the reaction did not proceed which can be attributed to catalyst dissociation via formation of perchloric acid. Same catalytic system was tested for ROP of VL. It was found to be effective for ROP of VL, and the polymerizations proceeded faster than that of CL. The polymerization results are summarized in Table 1 (Entries 9–14). PVL was also characterized by 1 H NMR spectroscopy (see Fig. 5). In order to get insight into mechanism, oligomer was synthesized using [CL]:[BnOH]:[cat] in ratio 40:1:1, and the resultant reaction mixture was characterized by 1 H NMR spectroscopy (see Fig. 6). The presence of BnOH endfunctionalized PCL supports the activated monomer mechanism (see Scheme 1). The observed broadening in 1 H NMR spectrum is probably due to the presence of residual copper(II). In summary, linear, hyperbranched and end-functionalized PCL and PVL were synthesized using commercially available Cu(ClO4 )2 ·6H2 O catalyst under solventfree conditions at room temperature. The polymerizations are living in nature and proceed via an activated monomer mechanism. The polymers were characterized by 1 H NMR, GPC and thermal analysis. M n of the obtained polymers are less than the theoretical M n probably due to slow propagation rates. A variety of biocompatible

Copper(II)-Catalyzed Ring Opening Polymerization of Cyclic Esters

81

f b+b’ c+c’+e+e’

d+d’

f’

a

g

Fig. 3 1 H NMR of Cu(ClO4 )2 ·6H2 O-catalyzed ROP of CL using pentaerythritol as initiator maintaining [CL]:[cat]:[init] ratio 200: 1: 1 (in CDCl3 )

Fig. 4 DSC thermogram of hyperbranched PCL obtained from Cu(ClO4 )2 ·6H2 O-catalyzed ROP of CL using pentaerythritol initiator

hyperbranched and end-functionalized polyesters for medical applications can easily be synthesized using this catalytic system. Extensive kinetic and mechanistic studies are under progress.

82

I. Jain and P. Malik

Table 1 Cu(ClO4 )2 ·6H2 O-catalyzed ROP of CL and VL using different initiators S. No

Initiator

Mon

[Mon]:[cat]:[init]

Conv. (%)a

Time (h)b

1

–

CL

200:1:1

94

7

2

BnOH

CL

200:1:1

98

4

3

BnOH

CL

200:1:5

99

2.5

4

BnOH

CL

500:1:1

98

5.5 2.2

5

Propargyl alcohol

CL

200:1:1

94

6

1,5-pentandiol

CL

200:1:1

95

5.5

7

Pentaerythritol

CL

200:1:1

75

7 6

8

Dipentaerythritol

CL

200:1:1

80

9

BnOH

VL

200:1:1

99

3

10

BnOH

VL

200:1:5

99

2.3 1.7

11

Propargyl alcohol

VL

200:1:1

96

12

1,5-pentandiol

VL

200:1:1

94

4.5

13

Pentaerythritol

VL

200:1:1

78

5.5

14

Dipentaerythritol

VL

200:1:1

81

4.7

a

Determined by 1 H NMR spectroscopy. b Time taken till the stirring was ceased at high speed (2070 rpm)

Scheme 1 Proposed mechanism for Cu(ClO4 )2 ·6H2 O catalyzed ROP of CL

M n (kg/mol) 5.9

5.7

f+f’

d+e

c+c

a

9

8

7

6

5

4

d’+e’

1.71 18.47 1.08 1.59 36.43

1.00 17.30

b

10

83

2.5912 2.5771 2.5632 2.3698 2.3564 2.3427 1.9443 1.9412 1.9302 1.9173 1.8966 1.8857 1.8767 1.8742 1.8625 1.7171 1.6942 1.6884

7.2841

4.3746 4.3630 4.3520 4.1089 4.0971 4.0862

Copper(II)-Catalyzed Ring Opening Polymerization of Cyclic Esters

3

2

1

0

ppm

Fig. 5 1 H NMR of Cu(ClO4 )2 ·6H2 O-catalyzed ROP of VL using propargyl alcohol as initiator maintaining [VL]:[cat]:[init] ratio 200:1:1(in CDCl3 )

9

8

7

6

3

1.3922

1.6502

2

2.50

4.66

3.6705

4

2.3130

4.0643

2.00

0.68

5

2.30

5.1176

0.70

10

0.17

I. Jain and P. Malik 7.3574 7.2832

84

1

0

ppm

Fig. 6 1 H NMR of Cu(ClO4 )2 ·6H2 O-catalyzed ROP of CL using BnOH as initiator maintaining [CL]:[cat]:[BnOH] ratio40:1:1(in CDCl3 )

References 1. Platel RH, Hodgson LM, Williams CK (2008) Biocompatible initiators for lactide polymerization. Polym Rev 48(1):11–63 2. Luckachan GE, Pillai CKS (2011) Biodegradable polymers—a review on recent trends and emerging perspectives. Polym Environ 19(3):637–676 3. Leja K, Lewandowicz G (2010) Polymer biodegradation and biodegradable polymers—a review. J Polym Environ Stud 19(2):255–266 4. Williams CK, Hillmeyer MA (2008) Polymers from renewable resources: a perspective for a special issue of polymer reviews. Polym Rev 48(1):1–10 5. Chen CK, Huang PK, Law WC, Chu CH, Chen NT, Lo LW (2020) Biodegradable polymers for gene-delivery applications. Int J Nanomedicine 15:2131–2150 6. Song R, Murphy M, Li C, Ting K, Soo C, Zheng Z (2018) Current development of biodegradable polymeric materials for biomedical applications. Drug Des Devel Ther 12(24):3117–3145 7. Brannigan RP, Dove AP (2017) Synthesis, properties and biomedical applications of hydrolytically degradable materials based on aliphatic polyesters and polycarbonates. Biomater Sci 20(1):9–21 8. Jedrzkiewicz D, Czelusniak I, Wierzejewska M, Szafert S, Ejfler J (2015) Well-controlled, zinc-catalyzed synthesis of low molecular weight oligolactides by ring opening reaction. J Mol Catal A: Chem 396:155–163 9. Lyubov DM, Tolpygin AO, Trifonov AA (2019) Rare-earth metal complexes as catalysts for ring-opening polymerization of cyclic esters. Coord Chem Rev 392:83–145

Copper(II)-Catalyzed Ring Opening Polymerization of Cyclic Esters

85

10. Gao J, Zhu D, Zhang W, Solan G, Ma Y, Sun WH (2019) Recent progress in the application of group 1, 2 & 13 metal complexes as catalysts for the ring opening polymerization of cyclic esters. Inorg Chem Front 6(10):2619–2652 11. Fazekas E, McIntosh RD (2020) Multinuclear catalysts for the ring-opening polymerisation of cyclic esters. Organometall Chem 43:63–82 12. Chamberlain BM, Jazdzewski BA, Pink M, Hillmyer MA, Tolman WB (2000) Controlled polymerization of dl-lactide and ε-caprolactone by structurally well-defined alkoxo-bridged di- and triyttrium(III) complexes. Macromolecules 33(11):3970–3977 13. Nomura N, Taira A, Nakase A, Tomioka T, Okada M (2007) Ring-opening polymerization of lactones by rare-earth metal triflates and by their reusable system in ionic liquids. Tetrahedron 63(35):8478–8484 14. Thibault M, Fontaine F (2010) Aluminium complexes bearing functionalized trisamido ligands and their reactivity in the polymerization of ε-caprolactone and rac-lactide. Dalton Trans 39(24):5688–5697 15. Motala-Timol S, Bhaw-luximon A, Jhurry D (2005) Kinetic study of the Al-Schiff’s base initiated polymerization of ε-caprolactone and synthesis of graft poly(methylmethacrylate-bcaprolactone). Macromol Symp 231(1):69–80 16. Jacobs C, Dubois P, Jerome R, Teyssie P (1991) Macromolecular engineering of polylactones and polylactides. 5. Synthesis and characterization of diblock copolymers based on poly-ε-caprolactone and poly(L,L or D,L) lactide by aluminum alkoxides. Macromolecules 24(11):3027–3034 17. Gowda RR, Chakraborty D (2010) Zinc acetate as a catalyst for the bulk ring opening polymerization of cyclic esters and lactide. J Mol Catal A: Chem 333(1):167–172 18. Lahcini M, Schwarz G, Kricheldorf HR (2013) Bismuth halide-catalyzed polymerizationsof ε-caprolactone. J Polym Sci A: Polym Chem 46(22):7483–7490 19. Lahcini M, Qayouh H, Yashiro T, Weidner SM, Kricheldorf HR (2011) Bismuth-triflatecatalyzed polymerizations of ε-caprolactone. Macromol Chem Phys 212(6):583–591 20. Kricheldorf HR, Weidner SM (2021) Polymerization of l-lactide with SnCl2 : a low toxic and eco-friendly catalyst. J Polym Environ 29(12):2504–2516 21. Kunioka M, Wang Y, Onozawa S-Y (2003) Polymerization of poly(ε-caprolactone) using yttrium triflate. Polym J 35(5):422–429 22. Hegea CS, Schiller SM (2014) Non-toxic catalysts for ring-opening polymerizations of biodegradable polymers at room temperature for biohybrid materials. Green Chem 16(3):1410– 1416 23. O’Keefe BJ, Breyfogle LE, Hillmyer MA, Tolman WB (2002) Mechanistic comparison of cyclic ester polymerizations by novel iron (III)-alkoxide complexes: single vs multiple site catalysis. J Am Chem Soc 124(16):4384–4393 24. Gibson VC, Marshall EL, Navarro-Llobet D, White AJP, Williams DJ (2002) A well-defined iron (II) alkoxide initiator for the controlled polymerisation of lactide. J Chem Soc, Dalton Trans (23):4321–4322 25. Trollsås M, Hedrick JL (1998) Dendrimer-like star polymers. J Am Chem Soc 120(19):4644– 4651 26. Trollsås M, Hedrick JL, Mecerreyes D, Dubois P, Jérôme R, Ihre H, Hult A (1997) Versatile and controlled synthesis of star and branched macromolecules by dentritic initiation. Macromolecules 30(26):8508–8511 27. Dong C-M, Qiu K-Y, Gu Z-W, Feng X-D (2001) Synthesis of star-shaped poly (ε-caprolactone)b-poly(dl-lactic acid-alt-glycolic acid) with multifunctional initiator and stannous octoate catalyst. Macromolecules 34(14):4691–4696 28. Pahl P, Schwarzenböck C, Fabian AD, Herz AD, Soller BS, Jandl C, Rieger B (2017) Corefirst synthesis of three-armed star-shaped polymers by rare earth metal-mediated group transfer polymerization. Macromolecules 50(17):6569–6576 29. Ren JM, McKenzie TG, Fu Q, Wong EHH, Xu J, An Z, Shanmugam S, Davis TP, Boyer C, Qiao GG (2016) Star polymers. Chem Rev 116(12):6743–6836

86

I. Jain and P. Malik

30. Deng E, Nguyen NT, Hild F, Hamilton IE, Dimitrakis G, Kingman SW, Lau P-L, Irvine DJ (2015) Molecular differentiated initiator reactivity in the synthesis of poly (caprolactone)based hydrophobic homopolymer and amphiphilic core corona star polymers. Molecules 20(11):20131–20145 31. Wang T-L, Huang F-J, Lee S-W (2002) Preparation and characterization of star polymers with polyurethane cores using polycaprolactone triol. Polym Int 51(5):1348–1352 32. Sanda F, Sanada H, Shibasaki Y, Endo T (2002) Star polymer synthesis from ε-caprolactone utilizing polyol/protonic acid initiator. Macromolecules 35(3):680–683 33. Zhao Y, Shuai X, Chen C, Xi F (2003) Synthesis and characterization of star shaped poly(llactide)s initiated with hydroxyl-terminated poly(Amidoamine) (PAMAM-OH) dendrimers. Chem Mater 15(14):2836–2843

Screening for Polythene-Degrading Bacteria from Dumped Soil Area and Its in vitro Microbial Polythene Degradation Romana Naaz and Weqar Ahmad Siddiqi

1 Introduction The plastic waste has become a major global issue due to a lack of disposal choices, recycling, and its lethal influence on the ecosystem and living animals. Every year, around 140 million tonnes of plastic are generated, with greater amounts detected in the biome as industrial waste products [1]. Plastics are macromolecule polymers made up of a repeating structure of monomers (plastics, starch, and proteins) linked by covalent bonds [2]. Plastics are the most prevalent non-biodegradable solid waste product, and they have recently been highlighted as a major hazard to aquatic life [3]. The plastic of today is LDPE, which is composed of organic and inorganic fundamental components such as carbon, silicon, nitrogen, oxygen, chlorine, and hydrogen. Plastic refers to a broad range of polymerised polymers and semi-synthetic materials. Although LDPE is an unavoidable need, inadequate waste treatment has resulted in severe pollution, necessitating the development of solutions for its degradation and management [4]. The process of breaking down natural or man-made materials using microorganisms is known as biodegradation. A biodegradable polymer is one whose degradation is assisted in part by a living system [5]. The most common non-biodegradable solid waste is polythene, which has recently been highlighted as a substantial risk for aquatic life. Plastic development is an issue for the environment since it produces garbage, has an influence on the ecosystem, and so poses a risk. The decomposition of plastic has not been a very productive endeavour. Polymer biological breakdown takes an unusually long time [6]. The proportional weight of plastic in solid urban waste has grown from less than 1% in the 1960s to more than 10% in the 2000s, due to the disposal of single-use plastics. Polyethylene (PE) (36%) and polypropylene and polyvinyl chloride (PVC) (20%) are the most often used plastics, followed by polyethylene (PE), polyurethane R. Naaz (B) · W. A. Siddiqi Department of Applied Sciences and Humanities, Faculty of Engineering and Technology, Jamia Millia Islamia, New Delhi 110025, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_9

87

88

R. Naaz and W. A. Siddiqi

(PU), and polystyrene (PS) with 10% each. As a result of improper handling, plastic waste is accumulating in both terrestrial and aquatic ecosystems [7]. Petroleum plastics, such as LDPE, are unavoidable, but inadequate waste management has resulted in significant environmental pollution, prompting the development of safer ways for dealing with their breakdown [8]. Patil claims that the opaque technique was used to test plastic-degrading microorganisms independently for bacteria and fungus The microorganisms Bacillus amylolyticus, Bacillus firmus, Pseudomonas putida, and Pseudomonas fluorescens were identified as having the potential to degrade commercial polythene carry bags composed of LDPE [9]. The work by Jayaprakash et al. shows that A. oryzae biosynthesised silver nanoparticles (AgNPs) may be used to clean up polyethene polymers. The phytotoxicity of polyethene reduced by AgNPs was also examined, and results were shown to be capable of degrading 64% of LDPE and 44% of HDP [10]. According to Alvi et al., polyethene biodegradation in the presence of Tatiana NPs (TNPs) was substantially stronger than alone or biodegradation without TNPs. The findings might have a significant impact on the development of eco-friendly shopping bags and other polyethene-based products [11]. Rasool and his colleagues find novel microorganisms that can help accelerate the breakdown of polyethene. Several landfills and dumpsites were surveyed for waste samples [12]. Bacterial and fungal species isolated from Pallikaranai and Chennai harbour waste soil samples were used to explore plastic biodegradation. According to Deepika and her colleagues, the opaque technique was employed in the individual plastic-degrading microorganisms for bacteria and fungi [13]. Kumar et al. found that heterotrophic bacteria isolated from mangrove soil might produce hydrolytic enzymes that help to break down polythene [14]. Sharma and colleagues discover significant potential in bioremediation to address the plastic waste problem, where current remediation technologies may be integrated and used with these species [15]. Polyethylene is expected to be destroyed successfully by natural soil microorganisms such as bacteria and fungus. In contrast, mushrooms and bacteria have the ability to degrade virgin polyethene in the laboratory [16]. The purpose of this study was to collect microorganisms from polluted soil, screen for potential plastic-degrading microorganisms, and identify high-potential plastic-degrading microorganisms.

2 Materials and Method 2.1 Sample Collection A top soil sample was taken near Jamia Millia Islamia University in New Delhi, from a plastic-dumped region.

Screening for Polythene-Degrading Bacteria …

89

2.2 Chemicals All the chemicals in the mineral salt media (MSM) were of high quality and purchased from Qualigens Fine Chemicals Ltd, Mumbai, and used without any further purification. Throughout the experiments, the glassware was thoroughly cleaned and autoclaved.

2.3 Media for Cultivation and Degradation Experiments The nutrient broth and agar were supplied by HIMEDIA Laboratories Ltd. Mineral salt media includes: K2 HPO4 , 1g; KH2 PO4 , 0.2g; NaCl, 1g; CaCl2 .2H2 O, 0.002g; (NH4 )2 SO4 , 1g; MgSO4 .7H2 O, 0.5g; CuSO4 .5H2 O, 0.001g; ZnSO4 .7H2 O, 0.001g; MnSO4 .H2 O, 0.001g; and FeSO4 .7H2 O, 0.01g. For degradation studies, compounds were autoclaved at 121 °C and 15-pound pressure for 15 min without the use of a carbon source medium. Soil samples were collected from the site and sealed in zip bags before being transported to the lab, where 1 g of soil was measured and diluted with sterile water.

2.3.1

Isolation of Polymer-Degrading Microorganisms

Serial dilution was used to extract the plastic-degrading bacteria from the soil. The soil sample was collected from a landfill near Jamia Millia Islamia University in New Delhi. Before being injected into sterilised mineral salt media (MSM), 1 g of soil was serially diluted from 10−1 to 10−9 . The obtained samples were serially diluted with sterile water in blank up to a 10−9 dilution, and the diluted samples were compared to the original samples. 10−1 , 10−2 , 10−3 , 10−4 , 10−5 , 10−6 , 10−7 , 10−8 , and 10−9 . The L-rod spread plate method was used to plate up to 20 µL of sterile nutrient agar onto sterile nutrient agar. The nutrient agar was incubated for 24 h at 37 °C.

2.4 Culturing of Microorganism The purpose of this study is to examine into the characteristics of a specific species. Pure cultures must be used to distinguish the species from other species. This pure culture was prepared using the streak plate method.

90

2.4.1

R. Naaz and W. A. Siddiqi

Spread Plate Technique

In a sterile Petri plate, 50 mL of nutrient agar was prepared, sterilised, and then set aside to solidify. To dilute the material, a tenfold dilution was utilised. A sterile micropipette was used to inject 0.1 mL of sample into the Petri plate for each dilution. A 0.1 mL sample was spread evenly over the agar surface with an L-rod-shaped cell spreader and incubated at 37 °C for 24 h to cultivate isolated colonies.

2.4.2

Streak Plate Technique

The microbial culture was distributed to the edge of the agar plate and then streaked out across the surface using the inoculation loop. As a result of the injection, the bacteria are sheared out and separated. These plates were incubated for 24 h at 37 °C.

2.5 Identification Test for Microorganism 2.5.1

Gram Staining Method

A sterile loop was used to generate a bacterial stain of culture on a clean grease-free slide. The stain was allowed to air dry before being heat fixed. After that, the staining reagents were used. Gram staining is a method for classifying microorganisms into two categories (gram +ve and gram −ve). Gram staining is nearly always the first step in identifying a bacterial organism when no specific culture is selected, and it is the default stain used by laboratories on a sample. The four basic components of grams staining (crystal violet, methyl violet), as well as the mordent (gram’s iodine) and de-colourised (ethyl alcohol, acetone, or 1:1 ethanol-acetone mixture), make a different colour (diluted carbon fuchsine, safranin, or neutral red). The stain was heat fixed before being treated with violet crystal for 30 s. After that, the slide was washed with distilled water. After 60 s, the stain was coated with gram’s iodine and iodine solution, and the straining agent was washed with a 95% absolute alcoholic solution. The stain was treated with safranin for 30 s before being examined under a microscope. The above-stained slide was examined under a microscope to assess the morphology of the chosen strain based on shape, size, and colour.

2.6 Identification Isolates based on morphological, cultural, and biochemical features were identified using Bergey’s Manual of Systematic Bacteriology. All isolates were subjected to gram staining and other biochemical tests [9].

Screening for Polythene-Degrading Bacteria …

91

2.7 Biochemical Test The isolated strains are biochemically identified using several manual biochemical procedures based on the pH-changing principle and substrate consumption. During incubation, organisms undergo metabolic changes that cause changes in the colour of the medium, which may be observed or recognised visually after the addition of a reagent.

2.7.1

Catalase Test

The catalase test was used to determine the catalase enzyme by inoculating the loop with the enzyme. After the culture sample was placed on the slide, the slide was supplemented with a 3% reduction in hydrogen peroxide applied to the slide drop by drop. Samples that formed bubbles yielded positive outcomes [12].

2.7.2

Hydrogen Sulphide Test

Some bacteria, such as Proteus Vulgaris, produce H2 S as a result of the breakdown of cysteine and methionine, which may be easily identified on Kliglers agar by a black precipitate on the streaking or stabbing side. The dark precipitate is ferrous sulphide, which is produced when the ferrous ion reacts with H2 S.

2.7.3

Methyl Red

Anaerobic glycolysis produces so many acids in some microorganisms that the system’s buffering effect is exceeded. At a pH of 4.4 or below, MR is a pH indicator that stays red. The sterilisation and production of the MR broth media had been completed. The MR broth media had been produced and sterilised. The sterilising and preparation of the MR broth medium was completed. After inoculating the test organisms, the tubes were put in the incubator for 24 h, and the methyl red indicator was added to the tubes, and the colour shift was observed. The red colour production yields a positive result, whereas the yellow colour production yields a negative result [13].

2.7.4

Mannitol Test

This test is commonly used to determine if bacteria can ferment sugar mannitol. The pH on the media becomes acidic as a result of the acids generated if organisms consume mannitol agar. The colour of the media changes from red to yellow, indicating a positive results [12].

92

2.7.5

R. Naaz and W. A. Siddiqi

Citrate Utilisation Test

This test determines if bacteria can convert citrate (Kreb’s intermediate cycle) to oxaloacetate (intermediate cycle for other Kreb’s). Citrate is the only source of carbon for bacteria in this medium. Bacteria cannot live if bacteria cannot utilise citrate. This is a good sign if the bacteria grow, and the medium turns deep blue as the temperature increases.

2.7.6

Starch Utilisation Test

The bacteria are inoculated onto starch agar plates and cultured for 24–48 h at 37 °C. Gram’s iodine was sprinkled throughout the inoculated portion of the plate as well as an inoculated area away from the inoculum. The inoculum is surrounded by a clean zone. The findings are comparable between infected and non-affected regions [13].

2.7.7

Motility Test

The hanging drop technique is the simplest way to study living microorganisms and their motility. In this approach, the organism is observed in a drop suspended in a concave slide under a cover pane. In a light microscope, the hanging drop slides are generally visible. The covers and cavity slides were cleaned and washed with alcohol after being rinsed with filtered water. Vaseline was applied to the four corners of the coverslip. A drop of culture was placed in the centre of the cover. The cavity slip was put over the cover, and the coverslip and slide were connected by the Vaseline. The cavity slip was placed over the cover, and the Vaseline was used to join the coverslip and slide. The drop edge has been inspected under the light microscope once the slide has been upright [17].

2.7.8

Gelatinase Test

Suspension from cultural media was prepared. This suspension is pipetted into two tubes containing gelatine agar base. Both tubes were kept in an incubator at 37 °C. After 4 h, one tube was tested, and another after 24 h. The reading was recorded after 30 min and compared to a blank gelatine agar tube.

2.7.9

Urease Test

Inoculate a urea agar slant with 1–2 drops of a well-isolated colony overnight. Incubate the tube in ambient air at 35–37 °C for 48 hours to 7 days, with the loosely cap. Keep an eye out for the development of pink colour for up to 7 days.

Screening for Polythene-Degrading Bacteria …

2.7.10

93

Microbiological Degradation of Plastics

Plastic samples with a diameter of 3 × 4.5 cm were made from polythene bags and buried in the dumped plastic area. Similar sized samples were transferred aseptically to conical flasks containing 250 mL MSM media and inoculated with various bacterial species. As a control, plastic discs in microbe-free media were used. Separate flasks with different microbial cultures were held in a shaker for each treatment. The polythene sample was recovered, properly washed with distilled water, shade-dried, and measured to estimate ultimate weight after one month of shaking. The data was used to calculate the weight loss of the plastics. The formula is used to calculate weight loss. %Weight loss = initial weight − final weight/initial weight × 100

3 Results and Discussion The focus of this research was to break down polythene using microorganisms isolated from dumped soil samples. A wide range of bacterial isolates was found in the soil samples. Screening, on the other hand, revealed just three significant bacterial colonies, morphological and biochemical traits were used to identify them. The identification and analysis of bacterial strains with plastics degradation capability were conducted in macroscopic and microscopic investigations and biochemical testing. The colony features, colour as well as microscopic tests including gram’s staining, spore staining, and a motility test have microscopically been determined for bacterial isolates.

3.1 Biochemical Properties of the Obtained Isolates Gram Staining Technique On a clean grease-free slide, a stain of the bacterial culture was produced using a sterile loop. Before heat-fixing the stain, it should be air-dried. Then it should be stained using the chemicals listed below. Saturated with crystal violet for 1 min, then washed with pure running water. Saturated again for 1 min with gram’s iodine, then washed with running distilled water. Gram’s decolouriser was then applied to the slide for 30 s. After that, the slide should be counterstained for 30 s with safranin before being washed with distilled water. Before analysing the cell morphology under a microscope, the slide should be air-dried. Gram-positive, gram-negative, and gram-positive rods were found in isolates 1, 2, and 3, respectively.

94

R. Naaz and W. A. Siddiqi

Mannitol Test By using mannitol agar colour changes to yellow, all three isolates exhibited a positive outcome shows in Fig. 2a [18]. Citrate Utilisation Test By using citrate as a carbon source, all three isolates produced a favourable result which is shows in Fig. 2b [17]. H2 S Test Figure 2c shows that all three isolates formed a black precipitate, indicating that they were all positive. Methyl Red Test The colour changes to red indicated in Fig. 2d, and all three isolates had favourable outcomes. Catalase Test This test yielded positive results for all three isolates by producing bubbles [6]. Starch Hydrolysis Test After 48 h, all three isolate from the clear zone around them [12]. Motility Test The three isolates are non-motile. Hydrolysis of Gelatine (Production of Gelatinase) Both the test tubes were not solidified after placing in refrigerator. Gelatine hydrolysis occurs. Hence, both strains were positive in result [12]. Urease Test Strains show a light pink colouration of medium hence positive result [12]. The bacteria were isolated by serially diluting the samples. The bacterial colonies that were obtained were white, cream, and yellowish in colour as shown Fig. 1. Three different bacterial strains were isolated and identified from gram staining and biochemical tests performed are Fig. 1a Arthobacter species, Fig. 1b as Pseudomonas species, and 1c as Bacillus species from the collected dumped soil. From Table 1, the results of the biochemical test for all samples are positive and non-motile. The percentage polythene weight reduction in MSM is shown in Table 2. The most active bacteria in 24.52 and 26.41% of LDPE in one month were discovered among Arthobacter sp. and Bacillus sp., respectively.

Screening for Polythene-Degrading Bacteria …

95

Fig. 1 Colony strain morphology based on serial dilution a Strain 1, b Strain 2, and c Strain 3

4 Conclusion Plastic-decomposing microorganisms were isolated from soil samples, and the weight loss technique was utilised to quantify the degradation of polythene bag strips by the separated microorganisms. Standard biochemical procedures were used to identify Arthobacter sp., Pseudomonas sp., and Bacillus sp. in the isolates. After inoculating the identified species into various culture conditions, weight loss after 30 days was used to assess their bio degradative efficiency, and it was determined that bacterial species. Without using any MSM, the polythene bag strips buried in natural soil at Jamia Millia Islamia University exhibit no weight difference after one month owing to natural bacterial activity. The Bacillus strains were shown to be more capable of breaking down LDPE than two bacterial strains obtained from a landfill.

Starch

+ve

+ve

+ve

Catalase

+ve

+ve

+ve

S. No.

Sample 1

Sample 2

Sample 3

Table 1 Result of biochemical test

+ve

+ve

+ve

Mannitol

+ve

+ve

+ve

H2 S

+ve

+ve

+ve

Citrate utilisation

+ve

+ve

– ve

Methyl red

Non-motile

Non-motile

Non-motile

Motility

+ve

+ve

+ve

Urease

+ve

+ve

+ve

Gelatine test

96 R. Naaz and W. A. Siddiqi

Screening for Polythene-Degrading Bacteria …

97

Fig. 2 Biochemical tests: a gelatine test, b mannitol test, c citrate utilisation test, d urease test e H2 S test, f methyl red test, g catalase test, (a) Strain 1, (b) Strain 2, and (c) Strain 3

98

R. Naaz and W. A. Siddiqi

Table 2 Results of plastic sample deterioration after one month by bacteria Strain no.

Initial weight (mg)

Final weight (mg)

Difference

% weight loss

Strain 1

0.053

0.050

0.003

5.66

Strain 2

0.053

0.051

0.002

3.77

Strain 3

0.053

0.049

0.004

7.547

Acknowledgements Romana Naaz, one of the authors, acknowledges financial support from the University Grants Commission (UGC), New Delhi, in the form of a non-NET fellowship.

References 1. Ghatge S, Yang Y, Ahn JH, Hur HG (2020) Biodegradation of polyethylene: a brief review. Appl Biol Chem 63. https://doi.org/10.1186/s13765-020-00511-3 2. Rose RS, Richardson KH, Latvanen EJ, Hanson CA, Resmini M, Sanders IA (2019) Microbial degradation of plastic in aqueous solutions demonstrated by CO2 evolution and quantification. bioRxiv. https://doi.org/10.1101/719476 3. Pandey P, Swati P, Yadav M, Tiwari A (2015) Nanoparticles accelerated in-vitro biodegradation of LDPE: a review. Pelagia Research Library Adv Appl Sci Res 6:17–22 4. Botre S, Jadhav P, Saraf L, Rau K, Wagle A (2015) Screening and isolation of polyethylene degrading bacteria from various sources. Int Res J Environ Sci (International Science Congress Association) 4:58–61 5. Scott G (1999) Antioxidant control of polymer biodegradation. Macromol Symp 144:113–125 (1999). https://doi.org/10.1002/masy.19991440111 6. Divyalakshmi S, Subhashini A (2016) Screening and isolation of polyethylene degrading bacteria from various soil environments. IOSR J Environ Sci. 10:1–7 7. Gambarini V, Pantos O, Kingsbury JM, Weaver L, Handley KM, Lear G (2021) Phylogenetic distribution of plastic-degrading microorganisms. mSystems 6:1–13 (2021). https://doi.org/10. 1128/msystems.01112-20 8. Bhatia M, Girdhar A, Chandrakar B, Tiwari A (2013) Implicating nanoparticles as potential biodegradation enhancers: a review. J Nanomed Nanotechnol 4. https://doi.org/10.4172/21577439.1000175 9. Patil RC (2018) Screening and characterization of plastic degrading bacteria. Br J Environ Sci 6:33–40 10. Jayaprakash V, Palempalli UMD (2019) Studying the effect of biosilver nanoparticles on polyethylene degradation. Appl Nanosci (Switzerland). 9:491–504. https://doi.org/10.1007/ s13204-018-0922-6 11. Alvi S, A Qazi I (2016) Survivability of polyethylene degrading microbes in the presence of titania nanoparticles. J Nanomater Mol Nanotechnol. 05. https://doi.org/10.4172/2324-8777. 1000185 12. Afreen B, Nouman Rasoo NR, Saima I (2020) Characterization of plastic degrading bacteria isolated from landfill sites. Int J Clin Microbiol Biochem Technol 4:30–35. https://doi.org/10. 29328/journal.ijcmbt.1001013 13. Deepika RC, Janani R, Vignesh R, Charu Deepika R, Manigandan P, Janani R (2016) Screening of plastic degrading microbes from various dumped soil samples. Int Res J Eng Technol 2493– 2498 14. Kumar S, Hatha AAM, Christi KS (2007) Diversity and effectiveness of tropical mangrove soil microflora on the degradation of polythene carry bags. Revista de Biologia Tropical 55:777– 786. https://doi.org/10.15517/rbt.v55i3-4.5954

Screening for Polythene-Degrading Bacteria …

99

15. Sharma J, Nandy K (2015) Isolation and characterization of plastic degrading bacteria from soil collected from the dumping grounds of an industrial area bioremediation view project extraterrestrial phosphate: the sole source of nourishment for terrestrial Microbes View project. 3:225–232 16. Muhonja CN, Makonde H, Magoma G, Imbuga M (2018) Biodegradability of polyethylene by bacteria and fungi from Dandora dumpsite Nairobi-Kenya. PLoS ONE 13:1–18. https://doi. org/10.1371/journal.pone.0198446 17. Thakur P: Screening of plastic degrading bacteria from dumped soil area project submitted in partial fulfillment of the requirement of master of science in life science 18. Jumaah OS (2017) Screening of plastic degrading bacteria from dumped soil area. IOSR J Environ Sci Toxicol Food Technol 11:93–98. https://doi.org/10.9790/2402-1105029398

Investigations on Excellent Selectivity and Performance for Removal of Anionic Azo Dyes from Wastewater Using Terephthalaldehyde Crosslinked Chitosan Copolymerized with Acrylamide Madhvi Garg and Dhiraj Sud

1 Introduction Dyes are the chemicals which usually discharged in water bodies globally via various dyeing industries. These chemicals damage aesthetic value of the water, prevent light penetration in water and resultantly affect photosynthesis [1]. Due to their accumulation in food chain, there is a dire need for its removal from aqueous system [2]. Numerous methods for treatment of water bodies are available like coagulation [3], flocculation [4], electrochemical oxidation [5], ozonation, ion exchange method [6], photocatalysis [7, 8] and nanotechnology [9]. But we need efficient and eco-friendly method out of available methods, and it is adsorption technology using biomaterial [10]. For adsorption method, various biomaterials like cellulose [11] and sodium alginate [12, 13] are used very frequently since last decades due to its desirable benefits [14]. From biomaterials, we have chosen chitosan due to its well-known features [15, 16]. Chitosan is a biopolymer of acetylated and deacetylated monomeric units obtained from naturally occurring polymer, chitin [17, 18]. It has comparatively high adsorption capacity, and it is cost-effective, easily accessible, thermally stable, photostable and biodegradable [19, 20]. Chitosan has various functional groups, i.e., amine and primary and secondary hydroxyl groups, which can be modified to get desirable properties [21]. The commonly used method for the modification of chitosan is chain elongation method which includes graft polymerization and crosslinking [22]. Among graft polymerization, grafting of vinyl monomers upon chitosan biopolymer is considered as one of the potent ways for the synthesis of adsorbent [23].

M. Garg (B) · D. Sud Department of Chemistry, Sant Longowal Institute of Engineering and Technology, Deemed to be University, Longowal, Sangrur 148106, India e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_10

101

102

M. Garg and D. Sud

Many research groups have synthesized composites or hydrogels from modified biopolymer using vinyl monomers. The chitosan/acrylamide hydrogel was synthesized which acts as super-hydrophilic/oleophobic filter [24]. The crosslinked polymer networks of poly (acrylic acid or acrylamide)/o-carboxymethyl acrylamide were synthesized and characterized. The studies show that it has super-porous nature resulting into good swelling capacity, which will be helpful in drug loading applications [25]. The semi-interpenetrating networks or composites of chitosan were synthesized by polymerizing acrylamide and using independent crosslinkers, N, Nmethylenebiscarylamide and epichlorohydrin. These composites are macroporous in nature and have good adsorption capacity of cationic dyes [26]. Our group member also has synthesized semi-interpenetrating hydrogel based on chitosan using vinyl monomer acrylic acid and utilized it for the controlled release of organophosphate pesticide, triazophos [27]. In this research article, we have synthesized novel crosslinked hydrogel by copolymerizing chitosan with a vinyl monomer, acrylamide, and then crosslinked it with terephthalaldehyde using potassium persulfate as initiator via ultrasonication technique. The synthesized CAAmT hydrogel was characterized and used for the adsorption of dyes. Further effect of adsorption parameters for the adsorption of two selected anionic dyes on CAAmT was analyzed. The selectivity of CAAmT for anionic dyes in multicomponent system was also checked, and reusability studies were done to check the economic value of synthesized CAAmT adsorbent. The interactions between hydrogel and dye molecule, which are responsible for the adsorption of dyes, have also been discussed in the last section.

2 Experimental Section 2.1 Materials Chitosan, acetic acid, potassium persulfate and terephthalaldehyde were purchased from HiMedia, India. Acrylamide and congo red were obtained from S.D. Fine Chem Limited and CDH Fine Chemicals, respectively. Solochrome dark blue, methyl orange, thymol blue and solochrome black were procured from Qualigens Fine Chemicals. All the solutions were prepared in millipore water.

2.2 Synthesis of Terephthalaldehyde Crosslinked Chitosan Hydrogel (CAAmT) For the synthesis of chitosan crosslinked hydrogel, chitosan was dissolved in 3% acetic acid and left overnight for dissolution [28]. To the above chitosan solution, acrylamide (5 mol L−1 ) was added with continuous stirring, and after 20–25 min,

Investigations on Excellent Selectivity and Performance …

103

potassium persulfate (0.125 mol L−1 ) was added and then crosslinking agent, terephthalaldehyde (0.025 mol L−1 ), was added after 15–20 min [29]. The reaction flask was then transferred in ultrasonic water bath for about 30 min to ensure homogenous crosslinking. The viscous reaction solution was then left for 1–2 days to set, and then, settled hydrogel was placed in oven after proper washing. Then, properly dried CAAmT hydrogel was weighed.

2.3 Characterization Terephthalaldehyde crosslinked chitosan hydrogel was characterized by physicochemical analysis. The vibrational spectra were taken in the range of 4000–450 cm−1 using the FTIR model Bruker Tensor27 system. Thermogravimetric analysis of crosslinked hydrogel was carried out in the range of 100–350 °C with heating rate 10 °C min−1 using TGA/SDTA 851e model. SEM–EDX was performed using JeolJSM-7610F PLUS. SEM images were taken at different magnifications, and EDX was taken from area of the SEM image.

2.4 Swelling Studies The swelling studies were conducted in water at different pH for which weight of swollen gel (CAAmT) was noted at different time intervals till the attainment of swelling equilibrium. The percentage swelling was calculated by the following equation Percentage swelling Weight of turgid gel − weight of dry gel × 100 = weight of dry gel

(1)

To get the idea of swelling kinetics, the following equation was applied to the obtained data Wt = ktn W∞

(2)

where W t and W ∞ are weight of gel at time t and at equilibrium, respectively, k is swelling rate front factor and n is swelling exponent. The value of n tells about which swelling mechanism is in action. The value of n < 0.5 refers to Fickian kinetics in which rate of diffusion is the rate-limiting step and n > 0.5 refers to non-Fickian kinetics in which rate of relaxation of polymeric chains is the rate-controlling step. The diffusion constant was calculated from the following Eq. (3)

104

M. Garg and D. Sud

  Wt Dt 1/2 =4 W∞ πl 2

(3)

where D is the diffusion constant (cm2 s−1 ) and l is the thickness of the CAAmT gel.

2.5 Adsorption Studies For investigating the potential of CAAmT to remove synthetic dyes, adsorption studies were performed by using 50 mg of adsorbent immersed in 50 mL of 10 ppm dye solutions at room temperature. The effect of pH, adsorbent dosage, temperature and concentration of the dye solution on adsorption capacity were checked by varying respective parameters. The decrease in dye concentration was measured from the absorbance of dyes at their respective λmax . The percentage adsorption was calculated from the following formula % Adsorption =

Ci − Ce × 100 Ci

(4)

where C i and C e are dye concentrations (mg L−1 ) initially and at equilibrium, respectively.

3 Results and Discussion 3.1 Synthesis The crosslinked chitosan hydrogel was synthesized by one of the greener synthesis routes, i.e., ultrasonication method, and the mechanism behind the synthesis of crosslinked polymer was free-radical polymerization. Similar synthesis mechanism was involved in previous research work done by our group [30]. The potassium persulfate, which was used as an initiator, generates free radicals of chitosan backbone as well as vinyl monomer, acrylamide, and initiates its polymerization and grafting on the biopolymer chitosan. Further, the free radicals of cross linker terephthalaldehyde were also generated, and it crosslinked with the copolymer of chitosan and polyacrylamide and resulted into the formation of crosslinked polymer, and it was denoted as CAAmT. The schematic representation for the synthesis of crosslinked chitosan hydrogel (CAAmT) is shown in Fig. 1.

Investigations on Excellent Selectivity and Performance …

105

Fig. 1 Schematic representation for the synthesis of CAAmT

3.2 FTIR FTIR spectra of CAAmT is shown in Fig. 2. The broadband around 3338 cm−1 is assigned to stretching vibration of hydroxyl and amide groups of chitosan and grafting monomer acrylamide. The shoulder peak at 2950 cm−1 corresponds to C-H stretching which confirms the grafting of acrylamide chains to the backbone chitosan. The peak at 2400 cm−1 shows CO2 adsorption from moisture. The band of medium intensity around 1600 cm−1 corresponds to C = O, C = N and N–H bending vibrations. The peaks at 1390 and 1100 cm−1 correspond to C-H bending, amine group deformation and C–O–C stretching vibrations. The rest of the peaks below 700 cm−1 were observed due to bending vibrations of N–H and CH2 rocking vibrations.

3.3 Thermogravimetric Analysis Thermogravimetric curve of CAAmT shown in Fig. 3 reveals that degradation occurs in four distinct steps. The first step observed at 86 °C corresponds to removal of water molecules which is equivalent to 7.9% of polymer mass. The second step corresponds to onset of degradation, observed at 293 °C, and 20% polymer mass was lost. The third step was observed at 383 °C and fourth step at 609 °C with 9.3% and 22.4% mass loss, respectively. The graph shows that 35% of the CAAmT polymer mass was left even at 700 °C. The DTG graph shows the first peak is symmetric around 86 °C which suggests that amine as well as hydroxyl groups will be evenly available for interaction with water molecules. It is due to the involvement of both groups in bonding with polyacrylamide and terephthalaldehyde. The second peak observed at 293 °C which is almost similar to pure chitosan [31] indicates that the crosslinking has not adverse effects on the thermal stability of CAAmT polymer.

106

M. Garg and D. Sud

Fig. 2 FTIR spectra of CAAmT

3.4 SEM–EDX The morphology of the crosslinked polymer surface can be analyzed from the SEM images, and quantification of the elements present in crosslinked polymer was confirmed from the EDX graph. The SEM images of the CAAmT taken at different magnifications are shown in the figure. The images show the fan palm leaf-like structures on the surface which confirm the crosslinking, and their even distribution is the proof of homogenous crosslinking. In higher magnified images (Fig. 4), leaf-like structures can be singly observed. The EDX graph (Fig. 4d) shows the presence of elements parallel to the calculated composition of CAAmT gel.

3.5 Swelling Studies The swelling studies data at different pH were plotted in graph (Fig. 5). The graph clearly depicts that maximum percentage swelling was obtained at pH 10 but fast swelling occurred in case of pH 2. The stability of the CAAmT gel was highest at pH 7, i.e., neutral pH. The swelling kinetics was applied to these data, and the value of n was calculated to be 0.27. The CAAmT gel follows Fickian behavior which means the rate of diffusion of water molecules in the polymer is less than rate of relaxation of polymeric chains. The diffusion constant value was calculated from the Formula (3), and its value is 3.18 × 10–8 cm2 s−1 .

Investigations on Excellent Selectivity and Performance …

Fig. 3 TGA-DTG curve of CAAmT

Fig. 4 SEM images at a 1000, b 2000, c 3000 magnification and d EDX graph of CAAmT

107

108

M. Garg and D. Sud

Fig. 5 Swelling graph of CAAmT at pH 2, 7 and 10

3.6 Adsorption Studies Adsorption experiment was carried out with CAAmT for the removal of anionic (congo red (CR), solochrome dark blue (SDB), methyl orange (MO), solochrome black (SB) and thymol blue (TB)) and cationic (malachite green (MG), methylene blue (MB) and methyl violet (MV)). The results revealed that CAAmT was selective for only anionic dyes. There is no adsorption in case of cationic dyes. The percentage adsorption for anionic dyes was calculated from the data obtained from UV spectra and represented in bar graph (Fig. 6). The percentage adsorption was appreciable in case of CR (96.2%) and SDB (92.1%) at pH 7 and 25 °C. The effect of pH, adsorbent dosage, temperature and concentration of dye solution was checked for the adsorption of CR and SDB dyes. Further adsorption isotherm and kinetics models were also applied for adsorption of these two dyes onto CAAmT.

3.7 Effect of pH, Adsorbent Dosage, Concentration, Temperature The batch adsorption experiment was performed to check the effect of pH of dye solution on adsorption capacity of CAAmT, and the results are presented in Fig. 7a. The pH of solution decides the surface charge of adsorbent and ionization of dye molecules which further play main role in efficiently adsorbing dye on the adsorbent CAAmT. The percentage adsorption of CR was maximum at pH 4 and of SDB was maximum at pH 6. At this pH, maximum amine groups transformed into NH3 + and more electrostatic attractions between anionic dyes and positively charged NH3 + groups resultantly increase the adsorption efficiency of CAAmT. At high pH, protons from dye solution are not available for protonation of amine groups due to which

Investigations on Excellent Selectivity and Performance …

109

Fig. 6 Adsorption of anionic dyes onto CAAmT

less NH3 + groups are there and CAAmT shows less affinity for both the anionic dyes [32]. Then, the effect of adsorbent dosage was also analyzed by varying the amount of adsorbent from 50 to 150 mg in 50 ml of 10 ppm dye solution (Fig. 7b). The adsorbent dosage correlates to adsorption sites available for dye molecules. The More adsorption sites and less steric repulsions between the adsorbing dye molecules consequently increase the percentage adsorption. The results revealed that 100 mg was optimum amount for maximum adsorption of both CR and SDB dyes. On increasing adsorbent dosage, density of adsorption sites increases due to which steric repulsions between dye molecules decrease the percentage adsorption. The batch adsorption experiments were performed to analyze the effect of initial concentration of dye solution (Fig. 7c). The optimum initial concentration of CR was 20 ppm and of SDB was 40 ppm beyond that percentage adsorption was decreased, but the adsorbed amount was increased. More the initial dye concentration, concentration gradient establishes between the adsorbate and adsorbent and drives the diffusion of a greater number of dye molecules into the crosslinked hydrogel. The effect of temperature was also checked upon the adsorption capacity of CAAmT. The optimum temperature for the adsorption of both dyes, i.e., maximum adsorption, was observed at 25 °C, but fast adsorption occurred at 32 °C (Fig. 7d). On increasing the temperature, the energy of molecules increased and movement of molecules increased due to which comparatively less dye molecules adsorbed onto the CAAmT surface.

3.8 Adsorption Isotherm The batch adsorption experiment data were fitted into Langmuir and Freundlich isotherm equations [Eqs. (5) and (6)], respectively, to understand the mechanism of adsorption and relation between the adsorbate and the adsorbent [33, 34].

110

M. Garg and D. Sud

Langmuir equation: Q e =

QbCe 1 + bCe

(5)

where Qe and C e are the maximum amount of dye adsorbed onto CAAmT and concentration of dye solution at equilibrium, respectively, Q (mg g−1 ) is the maximum amount of dye (CR and SDB) per unit weight of hydrogel and b (L mg−1 ) is the Langmuir constant which shows the affinity of binding sites. The straight-line plot between (C e /Qe ) and C e provides the values of Q and Langmuir constant, b. Freundlich equation : Q e = K f Ce1/n

(6)

where K f (mg g−1 ) is the Freundlich constant and 1/n is the intensity of adsorption. The values of K f and n were obtained from the intercept and slope of the straight-line plot between ln Qe and ln C e . The data of adsorption isotherm parameters obtained from isotherm plots (Fig. 8) are represented in Table 1.

Fig. 7 Effect of a pH, b adsorbent dosage, c initial concentration and d temperature on adsorption capacity of CAAmT

Investigations on Excellent Selectivity and Performance … Table 1 Adsorption isotherm parameters of CR and SDB adsorption

111

Isotherm models

Adsorption isotherm parameters

CR

SDB

Langmuir

Q (mg g−1 )

186

129.2

mg−1 )

0.1

b (L Freundlich

0.15

R2

0.95

K f (mg g−1 )

26.9

n

2.17

2.69

R2

0.99

0.92

0.97 25.4

3.9 Adsorption Kinetics The kinetics of the adsorption process was analyzed by applying kinetic models [pseudo-first-order (Eq. 7) and pseudo-second-order (Eq. 8)] to obtain experimental results [35, 36]. Pseudo-first-order equation: log(Q e − Q t ) = log Q e −

k1 t 2.303

(7)

Pseudo-second-order equation: t 1 t = + Qt k2 Q 2e Qe

(8)

where Qe and Qt are the amount of dye adsorbed (mg g−1 ) at equilibrium and time, t (min), respectively. The pseudo-first-order rate constant k 1 (min−1 ) was determined from the slope of the graph between log (Qe – Qt ) and t. The pseudo-second-order rate constant k 2 (g mg−1 min−1 ) was obtained from the intercept of the graph between t/Qt and t (Fig. 9). The parameters of adsorption kinetics analysis for dye adsorption are listed in Table 2. The adsorption of CR and MO onto CAAT and CAAG follows pseudo-second-order kinetics as suggested by a high value of correlation coefficient, R2 . The rate constant for adsorption of dyes (CR and MO) onto the adsorbents of CAAT and CAAG varies from 1.57 × 10–4 to 4.92 × 10–4 g mg−1 min−1 .

3.10 Multicomponent System and Reusability Studies For analyzing the operability of CAAmT in real industrial effluents, the adsorption studies in multicomponent system and reusability studies were also done [37]. The multicomponent system consists of anionic [congo red (CR), solochrome dark blue (SDB)] as well as cationic dyes [malachite green (MG) and methylene blue (MB)] of 10 ppm. The UV spectra of multicomponent system shown in Fig. 10 clearly

112

M. Garg and D. Sud

Fig. 8 Isotherm plots for CR and SDB adsorption Table 2 Adsorption kinetic parameters of CR and SDB adsorption

Kinetic models

Adsorption kinetic parameters

Pseudo-first order

k 1 (min−1 ) Qe Cal (mg g−1 )

0.05

SDB 0.0051

10.79

8.95

0.97

0.96

k2 × (g mg−1 min−1 )

18.08

5.09

Qe (mg g−1 )

15.38

11.45

0.99

0.98

R2 Pseudo-second order

CR

10–4

R2

Fig. 9 Pseudo-first-order and pseudo-second-order kinetic plots of CR and SDB adsorption

Investigations on Excellent Selectivity and Performance …

113

Fig. 10 UV spectra of multicomponent system

indicates that the intensity of the λmax of anionic dyes decreases and finally flattens, whereas in case of cationic dyes, there is no decrease in the intensity. The results revealed that percentage adsorption for both anionic dyes was decreased from which we can conclude that interactions between differently charged dye molecules do not affect the selectivity of CAAmT for anionic dyes. But the competition between anionic dyes for the adsorption sites available on CAAmT results into the reduction in percentage adsorption of both the dyes. The reusability potential of the synthesized CAAmT decides its applicability from economic point of view. The results of reusability studies reveal its efficacy up to five cycles (Fig. 11). In 5th adsorption cycle, percentage adsorption of CR was 46.3 and of SDB was 71.5 which is quite acceptable. Before using CAAmT for next adsorption cycle, it was washed in low pH water. At acidic pH, protons of low pH water help in desorbing the anionic dye molecules from adsorbent surface via electrostatic attractions. But the CAAmT was not stable at low pH, due to which it degrades, and sequentially its efficacy for adsorption of anionic dyes was decreased .

3.11 Interactions Between Crosslinked Hydrogel and Anionic Dyes The swelling studies results showed that maximum swelling occurred at alkaline pH and depicted that the surface of crosslinked hydrogel is positively charged. Therefore, interactions responsible for the adsorption of anionic dyes on crosslinked hydrogel are electrostatic attractions. Besides these attractions, there are π–π interactions between aromatic groups of terephthalaldehyde crosslinker and anionic azo

114

M. Garg and D. Sud

Fig. 11 Reusability cycles of CAAmT for CR and SDB adsorption

dyes which play vital role for the adsorption of anionic azo dyes. The π–π interactions between crosslinked hydrogel and anionic azo dyes are represented in scheme (Fig. 12).

Fig. 12 Schematic representation of π–π interactions between crosslinked hydrogel and anionic azo dyes

Investigations on Excellent Selectivity and Performance …

115

4 Conclusions The chitosan was copolymerized with acrylamide and crosslinked with terephthalaldehyde and characterized successfully. The swelling studies at different pH show its maximum stability, and swelling capacity was at alkaline pH, and it follow Fickian behavior in swelling kinetics. The results of adsorption studies for various industrial dyes revealed that CAAmT was selective for anionic dyes and showed excellent performance for congo red (CR) and solochrome dark blue (SDB). The percentage adsorption for CR and SDB was 96.2 and 92.1%, respectively. The optimization of all adsorption parameters, i.e., pH, adsorbent dosage, dye concentration, temperature, was done for these two anionic azo dyes on CAAmT. The adsorption isotherms were applied, and adsorption of CR and SDB follows Freundlich and Langmuir isotherm, respectively. The adsorption kinetics models were applied, and adsorption of both CR and SDB follows pseudo-second-order model. The results of multicomponent system of dyes show that selectivity of CAAmT for anionic dyes was retained. The reusability studies show that CAAmT was efficient up to five adsorption cycles.

References 1. Lellis B, Fávaro-Polonio CZ, Pamphile JA, Polonio JC (2019) Effects of textile dyes on health and the environment and bioremediation potential of living organisms. Biotechnol Res Innov 3(2):275–290 2. Berradi M, Hsissou R, Khudhair M, Assouag M, Cherkaoui O, El Bachiri A, El Harfi A (2019) Textile finishing dyes and their impact on aquatic environs. Heliyon 5(11):e02711 3. Kasperchik VP, Yaskevich AL, Bil’Dyukevich AV (2012) Wastewater treatment for removal of dyes by coagulation and membrane processes. Petrol Chem 52(7):545–556 4. Guibal E, Roussy J (2007) Coagulation and flocculation of dye-containing solutions using a biopolymer (Chitosan). React Funct Polym 67(1):33–42 5. Singh S, Lo SL, Srivastava VC, Hiwarkar AD (2016) Comparative study of electrochemical oxidation for dye degradation: parametric optimization and mechanism identification. J Environ Chem Eng 4(3):2911–2921 6. Liu CH, Wu JS, Chiu HC, Suen SY, Chu KH (2007) Removal of anionic reactive dyes from water using anion exchange membranes as adsorbers. Water Res 41(7):1491–1500 7. Kour S, Jasrotia R, Puri P, Verma A, Sharma B, Singh VP, Kalia S (2021) Improving photocatalytic efficiency of MnFe2O4 ferrites via doping with Zn2+/La3+ ions: photocatalytic dye degradation for water remediation. Environ Sci Pollut Res 1–16 8. Jasrotia R, Kumari N, Kumar R, Naushad M, Dhiman P, Sharma G (2021) Photocatalytic degradation of environmental pollutant using nickel and cerium ions substituted Co 0.6 Zn 0.4 Fe2O4 nanoferrites. Earth Syst Environ 1–19 9. Kunduru KR, Nazarkovsky M, Farah S, Pawar RP, Basu A, Domb AJ (2017) Nanotechnology for water purification: applications of nanotechnology methods in wastewater treatment. Water Purif 33–74 10. Ince M, Kaplan ˙Ince O (2017) An overview of adsorption technique for heavy metal removal from water/wastewater: a critical review. Int J Pure Appl Sci 3(2):10–19. https://doi.org/10. 29132/ijpas.358199 11. Thakur S, Verma A, Kumar V, Yang XJ, Krishnamurthy S, Coulon F, Thakur VK (2022) Cellulosic biomass-based sustainable hydrogels for wastewater remediation: chemistry and prospective. Fuel 309:122114

116

M. Garg and D. Sud

12. Verma A, Thakur S, Mamba G, Gupta RK, Thakur P, Thakur VK (2020) Graphite modified sodium alginate hydrogel composite for efficient removal of malachite green dye. Int J Biol Macromol 148:1130–1139 13. Thakur S, Sharma B, Verma A, Chaudhary J, Tamulevicius S, Thakur VK (2018) Recent progress in sodium alginate based sustainable hydrogels for environmental applications. J Clean Prod 198:143–159 14. Minamisawa M, Minamisawa H, Yoshida S, Takai N (2004) Adsorption behavior of heavy metals on biomaterials. J Agric Food Chem 52(18):5606–5611 15. Shariatinia Z, Jalali AM (2018) Chitosan-based hydrogels: preparation, properties and applications. Int J Biol Macromol 115:194–220 16. Sarode S, Upadhyay P, Khosa MA, Mak T, Shakir A, Song S, Ullah A (2019) Overview of wastewater treatment methods with special focus on biopolymer chitin-chitosan. Int J Biol Macromol 121:1086–1100 17. Chandy T, Sharma CP (1990) Chitosan-as a biomaterial. Biomater Artif Cells Artif Organs 18(1):1–24 18. Muxika A, Etxabide A, Uranga J, Guerrero P, De La Caba K (2017) Chitosan as a bioactive polymer: processing, properties and applications. Int J Biol Macromol 105:1358–1368 19. Tu H, Yu Y, Chen J, Shi X, Zhou J, Deng H, Du Y (2017) Highly cost-effective and highstrength hydrogels as dye adsorbents from natural polymers: chitosan and cellulose. Polym Chem 8(19):2913–2921 20. Liu C, Bai R (2014) Recent advances in chitosan and its derivatives as adsorbents for removal of pollutants from water and wastewater. Curr Opin Chem Eng 4:62–70 21. Mourya VK, Inamdar NN (2008) Chitosan-modifications and applications: opportunities galore. React Funct Polym 68(6):1013–1051 22. Prashanth KH, Tharanathan RN (2007) Chitin/chitosan: modifications and their unlimited application potential—an overview. Trends Food Sci Technol 18(3):117–131 23. Prashanth KH, Tharanathan RN (2003) Studies on graft copolymerization of chitosan with synthetic monomers. Carbohyd Polym 54(3):343–351 24. Kordjazi S, Kamyab K, Hemmatinejad N (2020) Super-hydrophilic/oleophobic chitosan/acrylamide hydrogel: an efficient water/oil separation filter. Adv Compos Hybrid Mater 3:167–176 25. Yin L, Fei L, Cui F, Tang C, Yin C (2007) Superporous hydrogels containing poly (acrylic acidco-acrylamide)/O-carboxymethyl chitosan interpenetrating polymer networks. Biomaterials 28(6):1258–1266 26. Dragan ES, Lazar MM, Dinu MV, Doroftei F (2012) Macroporous composite IPN hydrogels based on poly (acrylamide) and chitosan with tuned swelling and sorption of cationic dyes. Chem Eng J 204:198–209 27. Bhullar N, Rani S, Kumari K, Sud D (2021) Amphiphilic chitosan/acrylic acid/thiourea based semi-interpenetrating hydrogel: solvothermal synthesis and evaluation for controlled release of organophosphate pesticide, triazophos. J Appl Polym Sci 138(25):50595 28. Bhullar N, Kumari K, Sud D (2018) A biopolymer-based composite hydrogel for rhodamine 6G dye removal: its synthesis, adsorption isotherms and kinetics. Iran Polym J 27(7):527–535 29. Garg M, Bhullar N, Bajaj B, Sud D (2021) Terephthalaldehyde as a good crosslinking agent in crosslinked chitosan hydrogel for the selective removal of anionic dyes. New J Chem 45(11):4938–4949 30. Bhullar NK, Kumari K, Sud D (2019) Semi-interpenetrating networks of biopolymer chitosan/acrylic acid and thiourea hydrogels: synthesis, characterization and their potential for removal of cadmium. Iran Polym J 28(3):225–236 31. Neto CDT, Giacometti JA, Job AE, Ferreira FC, Fonseca JLC, Pereira MR (2005) Thermal analysis of chitosan based networks. Carbohyd Polym 62(2):97–103 32. Almasian A, Mahmoodi NM, Olya ME (2015) Tectomer grafted nanofiber: synthesis, characterization and dye removal ability from multicomponent system. J Ind Eng Chem 32:85–98

Investigations on Excellent Selectivity and Performance …

117

33. Foo KY, Hameed BH (2010) Insights into the modeling of adsorption isotherm systems. Chem Eng J 156(1):2–10 34. Dada AO, Olalekan AP, Olatunya AM, Dada OJIJC (2012) Langmuir, freundlich, temkin and dubinin-radushkevich isotherms studies of equilibrium sorption of Zn2+ unto phosphoric acid modified rice husk. IOSR J Appl Chem 3(1):38–45 35. Popoola, L. T.: Characterization and adsorptive behaviour of snail shell-rice husk (SS-RH) calcined particles (CPs) towards cationic dye. Heliyon 5(1), e01153 (2019). 36. Cheng C, Liu Z, Li X, Su B, Zhou T, Zhao C (2014) Graphene oxide interpenetrated polymeric composite hydrogels as highly effective adsorbents for water treatment. RSC Adv 4(80):42346– 42357 37. Chen B, Yue W, Zhao H, Long F, Cao Y, Pan X (2019) Simultaneous capture of methyl orange and chromium (VI) from complex wastewater using polyethylenimine cation decorated magnetic carbon nanotubes as a recyclable adsorbent. RSC Adv 9(9):4722–4734

The Effect of the Adding of Banana Sap on the Properties of PEGDMA/PEO Hydrogel Film Sap for Wound-Healing Acceleration Haryanto, Fena Retyo Titani, Nunuk Aries Nurulita, and Achmad Chafidz

1 Introduction Over the last decades, hydrogel has been applied in various medical applications such as drugs delivery, wound dressing and contact lenses [1]. Hydrogel is a type of hydrophilic macromolecule polymers in the form of a network of crosslinking. It has the capability to absorb and retain water (swelling) [2–5]. Some kinds of wound dressing are applied in the medical area, i.e. semi-permeable film, hydrocolloid and hydrogel. The wound dressing must be simple to be used, painless when removed from the wound and require fewer replacement pads on the usage [6]. One of the very promising biomaterials is hydrogel. The term is usually used for biomaterial used in biomedical purposes. Hydrogel is an ideal dressing because it can facilitate the autolytic debridement of necrosis and able to absorb the exudates. Nevertheless, hydrogel has some weaknesses such as easily destroyed and low mechanical strength [7]. Various methods can be applied for developing crosslinked hydrogels such as physical, chemical and radiation methods. Among them, gamma ray radiation [8] and electron beam radiation [9] are relatively easy to initiate crosslinking, scission or grafting reactions in order to modify polymeric material properties [10]. The electron beam irradiation technique is more advantageous compared to others due to the ease of radiation dose control and the experimental conditions straight forward for mass production of products, and also, the final product is free from various impurities such as residues from initiators, retarders and/or accelerators which are used in chemical Haryanto (B) · F. R. Titani Chemical Engineering Department, Universitas Muhammadiyah Purwokerto, Purwokerto, Indonesia N. A. Nurulita Pharmacy Department, Universitas Muhammadiyah Purwokerto, Purwokerto, Indonesia A. Chafidz Chemical Engineering Department, Universitas Islam Indonesia, Yogyakarta 55584, Indonesia © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_11

119

120

Haryanto et al.

crosslinking techniques. Furthermore, the level of crosslinking and grafting can be monitored by controlling the radiation dose [11]. Hydrogel which has been developed over the years is the polymer base hydrogel without any additional drug which has an ability to accelerate the wound-healing process. So, to increase the rate of wound-healing process, hydrogel can be improved with the addition of banana sap (Musa paradisiaca). Banana sap contained saponin, antraquinon and quinon that can serve as antibiotics and pain killers [12, 13]. This research will be conducted to develop banana sap-loaded hydrogel for wounddressing applications. Banana sap was mixed with PEGDMA/PEO solution and irradiated using gamma ray.

2 Materials and Methods 2.1 Materials Polyethylene oxide (PEO) (Mn 600.000) and polyethylene glycol dimethacrylate (PEGDMA) (Mw 750) were purchased from Sigma-Aldrich.

2.2 Methods a.

Preparation of banana sap-loaded PEGDMA/PEO hydrogel

b.

Banana sap was added into 10% PEGDMA/PEO solution in the concentration of 0, 3, 6, 9, 12 and 15% w/w. It was mixed for 24 h. About 35 ml of solution was poured into petridish and then irradiated using gamma rays with the intensity of 40 kGy. After irradiation, the solution was dried in the oven for 72 h at 50 °C. Analysis of hydrogel Hydrogels were tested for some parameters such as gel fraction, swelling ratio, mechanical strength and surface morphology. The testing of the influence of the addition of banana sap on some parameters was run three times for each parameter.

The Effect of the Adding of Banana Sap on the Properties of PEGDMA/PEO …

121

80

Gel fraction (%)

78 76 74 72 70 68 66 0

3

6

9

12

15

Banana sap concentration (%) Fig. 1 Effect of banana sap concentration on gel fraction of hydrogel

3 Results and Discussions 3.1 The Effect of Banana Sap Concentration on Gel Fraction of PEGDMA/PEO Hydrogel Figure 1 shows the effect of banana sap concentration on gel fraction of hydrogel. The gel fraction increases by increasing the content of banana sap in the hydrogel. The increasing of gel fraction indicates that the more number of crosslinking occurred in hydrogel. This is may be caused by the content of hydroxyl group in banana sap that attacks the radical backbone of PEGDMA/PEO that initiates the hydrogen bonding to increase the crosslinking process.

3.2 The Effect of Banana Sap Concentration on Swelling Ratio of PEGDMA/PEO Hydrogel Swelling ratio is the main property of hydrogel especially for wound-dressing application. The higher value of swelling ratio indicates the higher ability of hydrogel to absorb the excudate of wound. Swelling ratio increased by increasing the time, but swelling ratio at 30 min is just a bit difference for all concentrations of banana sap

122

Haryanto et al. 1200 1100 1000

Swelling ratio (%)

900 800 700 600 500 0% 3% 6% 9% 12% 15%

400 300 200 100 0 0

5

10

15

20

25

30

35

Time (Minutes)

Fig. 2 Swelling ratio of PEGDMA/PEO hydrogel on various banana sap concentrations

as shown in Fig. 2. The content of tanin and quinon in banana sap may cause the increase of swelling ratio.

3.3 The Effect of Banana Sap Concentration on Mechanical Strength of PEGDMA/PEO Hydrogel The results of tensile strength and elongation at break of hydrogel as the influence of the addition of banana sap are presented in Figs. 3 and 4. It can be concluded from Fig. 3 that the increase in concentration of banana sap results in lower tensile strength of hydrogel. This is due to the addition of banana sap into the hydrogel that causes the increase of the weak hydrogen bonding between hydroxyl group of banana sap with polymer of PEGDMA/PEO, thereby the tensile strength also decreases. In contrast to tensile strength, the elongation at break increases significantly as shown in Fig. 4.

3.4 SEM Analysis One of the most important properties of hydrogel that must be considered is microstructure morphologies. The grafting affects the morphology of polymer backbone and also their physical, chemical and thermal properties. The surface morphology of the hydrogel and its amalgamated structures are shown in two states like native and crosslinked. Therefore, SEM was used to study the morphological changes in the hydrogel. SEM images of hydrogel (Fig. 5) revealed rough agglomer-

The Effect of the Adding of Banana Sap on the Properties of PEGDMA/PEO …

123

Fig. 3 Effect of banana sap concentration on tensile strength

Fig. 4 Effect of banana sap concentration on percentage of elongation

ated and wave-type structure, whereas Fig. 6 showed rough surface with porous-type structure. These micrographs obviously show the variation in chemical structures and changed surface morphology in crosslinked networks.

124

Haryanto et al.

Fig. 5 Morphology of hydrogel PEGDMA/PEO

Fig. 6 Morphology of banana-loaded PEO/PEGDMA hydrogel

3.5 In Vivo Analysis Results of in vivo analysis as seen in Fig. 7 are that the addition of banana sap could accelerate the wound-healing rate and shows the better effect compared to gauze control. It may be caused by the influence of some compound in banana sap such as saponin and flavanoid which has a better effect to cure a wound as mentioned in some research results [10].

4 Conclusions According to the results and discussion, it can be concluded that the addition of banana sap into PEGDMA/PEO solution can increase fraction gel, swelling ratio and

The Effect of the Adding of Banana Sap on the Properties of PEGDMA/PEO …

125

Fig. 7 Size reduction (%) of healing process

the percentage of elongation at break of hydrogel film. On the contrary, the tensile strength decreases by the increase in concentration of banana sap. Furthermore, banana sap could accelerate the wound-healing rate. These results show the potential of banana sap-loaded PEO/PEGDMA hydrogel for wound-dressing application. Acknowledgements This work was financially supported by Ministry of Research, Technology and Higher Education (T/140/E3/RA.00/2019).

References 1. Rajendran S, Anand SC (2002) Developments in medical textiles. Text Prog 32:1–42. https:// doi.org/10.1080/00405160208688956 2. Jones L, Maya C, Nazar L, Simpson T (2002) In vitro evaluation of the dehydration characteristics of silicone hydrogel and conventional hydrogel contact lens materials. Contact Lens Anterior Eye 25:147–156. PII: S1367–0484(02)00033–4 3. Soler DM, Y. Rodriguez Y, Correa H, Moreno A, Carrizales L (2012) Pilot scale-up and shelf stability of hydrogel wound dressings obtained by gamma radiation, Radiat Phys Chem 81:1249-1253. https://doi.org/10.1016/j.radphyschem.2012.02.024 4. Kaetsu I et al (1979) Immobilization of enzymes by radiation. Radiat Phys Chem 14:595–602. https://doi.org/10.1016/0146-5724(79)90094-3 5. Kumakura M, Kaetsu I (1984) Behaviour of enzymes activity in immobilized. proteases. Int J Biochem 16:1159–1161. https://doi.org/10.1016/0020-711x(84)90010-7 6. Abdelrahman T, Newton H (2011) Wound dressing: principles and practice. Surgery 29:491495 7. Yoshii F et al (1999) Electron beam crosslinked PEO and PEO/PVA hydrogels for wound dressing. Radiat Phys Chem 55:133–138. https://doi.org/10.1016/S0969-806X(98)00318-1

126

Haryanto et al.

8. Nam SY, Nho YC, Hong SH et al (2004) Evaluations of poly(vinyl alcohol)/alginate hydrogels cross-linked by γ-ray irradiation technique. Macromol Res 12:219. https://doi.org/10.1007/ BF03218391 9. Salmawi KM, Ibrohim SM (2011) Characterization of superabsorbent carboxymethylcellulose/clay hydrogel prepared by electron beam irradiation. Macromol Res 19:1029. https://doi. org/10.1007/s13233-011-1006-6 10. Rosiak JM, Ulanski P (1999) Synthesis of hydrogels by irradiation of polymers in aqueous solution. Radiat Phys Chem 55:139–151. https://doi.org/10.1016/S0969-806X(98)00319-3 11. Mesquita AC, Mori MN Silva LGA(2004) Polymerization of vinyl acetate in bulk and emulsion by gamma irradiation Radiat Phys Chem71:251. https://doi.org/10.1016/j.radphyschem.2004. 03.048 12. Gupta B (2010) Textile-based smart wound dressings. Indian J Fibre Text Res 35:175–176 13. Haryanto, Aries Nurulita N, Sundhani E, Ho Huh P, Cheol KS (2018) Effect of molecular weight of poly(Ethylene Glycol) Dicarboxylate on the properties of cross-linked hydrogel film as an antiadhesion barrier. Polymer-Plastics Technol Eng 57:1393-1399. https://doi.org/10. 1080/03602559.2017.1381254

Synergistic Effect of Encapsulated Linseed Oil and Soybean Oil Blend in Phenol-Formaldehyde Microcapsule on Self-healing Efficiency of Anticorrosive Coatings P. S. Shisode , C. B. Patil , and P. P. Mahulikar

1 Introduction The global demand of metals is accelerated continuously due to their superior qualities like malleability, ductility, strength, electrical and thermal conductivity, etc. But, corrosion, the natural phenomena of metals create adverse impact on the utility, durability and strength of the metal. An efficient protection measure for metals is selfhealing coatings [1–6]. The microencapsulation approach for self-healing ensures sustained release of healing material. Drying oils like linseed oil is used as healant for many anticorrosive systems [7–10]. Linseed oil which is actually drying oil undergoes auto-oxidation with atmosphere oxygen in the drying or polymerization process when released from microcapsule [7, 11, 12]. However, for improved selfhealing performance, it is observed that the healing agent must have a sufficiently low viscosity to flow out of the ruptured microcontainer and completely cover crack within short time. Thus, in our previous work, the efficiency of urea–formaldehyde (UF) microcapsules with linseed oil was found to be increased when linseed oil was blended with less viscous soybean oil [12]. In extension to this, in the present work, efforts were made to study whether the shell material affects the efficiency of the blended oil microcapsules in anticorrosive coatings. The urea–formaldehyde shell material of microcapsules was replaced with phenol-formaldehyde (PF) shell material. Thus, PF microcapsules containing blends of linseed oil and soybean oil (PF-SLO) were prepared, and after characterization, their synergistic effect of anticorrosive

P. S. Shisode (B) · C. B. Patil Department of Chemistry, S. S. V. P. Sanstha’s L. K. Dr. P. R. Ghogrey Science College, Deopur, Dhule, M.S, India P. P. Mahulikar School of Chemical Sciences, Kavayitri Bahinabai Chaudhari North Maharashtra University, Jalgaon, M.S, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_12

127

128

P. S. Shisode et al.

property was studied in comparison with linseed oil (PF-LO) microcapsules in epoxy coatings.

2 Materials Polyvinyl alcohol (PVA), phenol, formaldehyde, resorcinol, ammonium chloride, xylene were purchased from (SD Fine Chemicals Limited). Soybean oil, epoxy resin (local supplier), linseed oil (Rarco Research Lab, Mumbai) and cobalt drier (Poonam Paints, Jalgaon) were used for experiments.

3 Preparation of Microcapsules The procedure was optimized for microcapsule preparation. The PF microcapsules of linseed oil (PF-LO) and microcapsules of soybean and linseed oil blends (PF-SLO) were synthesized separately by using in situ polymerization technique in oil-in-water emulsion. In three-neck round-bottom flask, 5 ml of 5 wt. % aqueous solution of polyvinyl alcohol (PVA) was added to 150 ml of deionized water. Mechanical stirrer was used for agitating the solution of reaction mixture. Under agitation, phenol (3.76 g) and ammonium chloride (0.5 g) were added to reaction mixture. Then, to adjust the pH of solution nearly to 7–8, an appropriate amount of NH4 OH was added. Then, slow addition of relevant drying oil combination (Table 1) was carried out to form stable emulsion through agitation for 30 min. Then, 37 wt. % of aqueous solution of formaldehyde (6.486 g) was added. The reaction was initiated by heating the reaction mixture to 65 °C and stirred constantly at 400 rpm for 2 h. Further, 5 wt. % of hydrochloric acid was added to adjust the pH at about 2–3. Subsequently, resorcinol (0.5 g) was added and reaction mixture was stirred at 65 °C for about 3 h. Finally, reaction mixture was cooled. Synthesized microcapsules were then filtered and washed with water followed by washing with xylene and then dried at room temperature [8, 13, 14]. Table 1 Combinations of drying oil for synthesis of microcapsules Prepared drying oil combination

Linseed oil (ml)

Soybean oil along with 0.5 wt. % of cobalt drier (ml)

LO

25.0

0.0

20% SLO

20.0

5.0

30% SLO

17.5

7.5

Synergistic Effect of Encapsulated Linseed Oil and Soybean Oil … Table 2 Oil content of samples

129

Composition

PF-LO

20% PF-SLO microcapsule

30% PF-SLO microcapsule

% oil content

88

89.50

90

4 Characterization The successful formation of microcapsules was observed under optical microscope initially, and then, the morphology of the synthesized microcapsule was analyzed using field emission scanning electron microscope (FE-SEM). The particle size analyzer was used to determine the mean diameter along with the size of these PF microcontainers. The core content entrapped in the synthesized PF microcapsules was determined by Soxhlet extraction, and the core and shell were used for FTIR analysis. The detailed description of these characterization is discussed in our previous report [15].

4.1 Formulation and Assessment of Corrosion Resistance of Formulated Coated Panels The prepared PF microcapsules were used for formulating PF/epoxy topcoat. Then, these formulations were coated on mild steel panels. Control specimen was prepared by applying epoxy topcoat without microcapsules, whereas for each PF-LO and PF-SLO incorporated specimen, 3 and 5% of each combination of prepared microcapsules were dispersed separately in 10 wt % solution of epoxy resin in xylene with hardener. The clean mild steel panel with dimensions 150 × 100 × 1 mm was coated manually only on single side. These coated panels were then allowed to cure and then used for immersion studies. The cross-cut crack was generated upon the metal surfaces by hand engraving with the help of a razor blade and then allowed to cure approximately for 24 h ambient temperature. Home-made equipment was utilized to perform immersion studies of these coated specimens. The samples were tested for a total exposure time of 240 h. The corrosion study of the cross-cut specimens was visually inspected using digital camera.

130

P. S. Shisode et al.

5 Results and Discussion 5.1 Analysis of Surface Morphology of Synthesized Microcapsules The microencapsulation of various drying oil combinations was monitored by an optical microscope (40 X and 100 X); their relevant encapsulation processes were (Fig. 1) found to be successful. The FE-SEM study (Fig. 2) supports the formation of spherical microcapsules with nonporous and rough shell wall. The spherical microcapsule helps in uniform dispersing while formulation of coating [7]. And, the nonporous shell wall of microcapsule may be helpful in avoiding leakages and diffusion of liquid healing agents.

a

b

c

Fig. 1 Optical microscopic images of synthesized a PF-LO microcapsules, b 20% PF-SLO microcapsules and c 30% PF-SLO microcapsules

a

b

c

Fig. 2 FE-SEM images of synthesized a shell morphology of PF-LO microcapsules, b 20% PFSLO microcapsules and c 30% PF-SLO microcapsules

Synergistic Effect of Encapsulated Linseed Oil and Soybean Oil …

a

131

b

Fig. 3 Particle size distribution of synthesized a PF-LO microcapsules and b 20% PF-SLO microcapsules

5.2 Particle Size Analysis of Synthesized Microcapsules Additionally, the size distribution curve of the prepared PF-LO microcapsules (Fig. 3a) showed that the size of microcapsule ranges from 15.56 to 352 µm, whereas the mean diameter was 122.7 µm for PF-LO microcapsules. The size of PF microcapsules containing blend of linseed and 20% soybean oil (20% PF-SLO) ranges from 4.62 to 418 µm, whereas the mean diameter was 149.8 µm (Fig. 3b).

5.3 The Core Content of the Synthesized Microcapsules The Soxhlet apparatus was used for determining the amount of relevant drying oil combination in PF microcapsules, and the observed maximum content is shown in Table 2. The maximum amount of encapsulated oil is essentially important in auto-healing of coating.

5.4 FTIR Analysis The Soxhlet extracted core and shell material of synthesized PF-LO and 20% PFSLO microcapsules were then subjected to spectroscopic studies (FTIR) to verify their chemical compositions. The FTIR spectra of core of blended 20% PF-SLO microcapsules (Fig. 4a) showed closely matching absorption bands with the reported data of neat soybean oil and neat linseed oil [12]. The characteristic absorption broad band observed at 3366–3200 cm−1 attributed to O–H stretching, while the band at 2102 cm−1 corresponded to C = C, the band at 1748 cm−1 attributed to -C = O stretching and the band at 1463 cm−1 characterized to C-H stretching. The FTIR

132

P. S. Shisode et al.

Fig. 4 FTIR spectra of a extracted core material of 20% PF-SLO microcapsules, b extracted core material of PF-LO microcapsules, c extracted shell material of PF-LO microcapsules and d extracted shell material of 20% PF-SLO microcapsules

Synergistic Effect of Encapsulated Linseed Oil and Soybean Oil …

133

c

d

Fig. 4 (continued)

spectrum of core material of PF-LO microcapsules (Fig. 4b) showed that absorption bands were found to be closely matching to the reported data of neat linseed oil [12]. It was observed from FTIR spectra of PF shell materials of PF-LO and 20% PFSLO (Fig. 4c and d) that the absorption bands were closely matching to the reported data of phenol-formaldehyde [13]. The observed absorption bands at 1608 cm−1 correspond to C = C aromatic ring vibrations for both PF-LO microcapsules shell

134

P. S. Shisode et al.

Table 3 Results of controlled released study at different time intervals Time (h)

0

Percentage of released drying oil from PF-LO microcapsules 0.000

Percentage of released drying oil combination from 20% PF-SLO microcapsules 0.000

Percentage of released drying oil combination from 30% PF-SLO microcapsules 0.000

2

40.00

46.00

48.00

4

53.00

55.00

56.00

6

66.00

67.00

70.00

8

70.50

73.00

75.00

10

88.00

89.50

90.00

materials and 20% PF-SLO microcapsules shell materials. The bands at 1259 cm−1 and 1170 cm−1 corresponded to -C-C-O asymmetric stretching vibrations and C-H plan deformations, respectively, for both PF shell materials, while band at 746 cm−1 indicates frequency of 2, 4, 6 tri-substituted phenol and the bands at 1369 and 1371 cm−1 correspond to phenol O–H bending vibration of PF-LO microcapsules shell materials and 20% PF-SLO microcapsules shell materials, respectively. The FTIR data of outer shell materials clearly supported that they were made of phenol-formaldehyde resin.

5.5 Control Release Study The loss on drying method was utilized to find out percent of core content released from the microcapsules, and results are summarized in Table 3. From the data, it was confirmed that the prepared microcapsules released core material from microcapsules in controlled manner and have good thermal stability. It was found that the prepared microcapsule releases about 88% linseed oil from PF-LO microcapsules in 10 h while about 89.50 and 90% of entrapped drying oil combinations from 20% PF-SLO and 30% PF-SLO microcapsules, respectively, in same period.

5.6 Efficiency of Self-Healing Coating in Corrosion Protection In current investigation, the corrosion resistance of coated specimens was determined by their immersion study in 5% NaCl solution. It clearly revealed (Fig. 5 and 6) that the significant corrosion process was seen for the controlled specimens and specimen with 3 and 5% PF-LO microcapsules within 192 h of immersion study.

Synergistic Effect of Encapsulated Linseed Oil and Soybean Oil …

135

Fig. 5 Corrosion test results of mild steel-coated specimens at zero hours (a neat epoxy panel, b 3% specimen of LO panel, c 5% specimen of LO panel, d 3% specimen of 20% SLO panel, e 5% specimen of 20% SLO panel, f 3% specimen of 30% SLO panel and g 5% specimen of 30% SLO panel)

Fig. 6 Corrosion test results of mild steel-coated specimens at 192 h (a neat epoxy panel, b 3% specimen of LO panel, c 5% specimen of LO panel, d 3% specimen of 20% SLO panel, e 5% specimen of 20% SLO panel, f 3% specimen of 30% SLO panel and g 5% specimen of 30% SLO panel)

136

P. S. Shisode et al.

Fig. 7 Corrosion test results of mild steel-coated specimens at 240 h (a neat epoxy panel, b 3% specimen of LO panel, c 5% specimen of LO panel, d 3% specimen of 20% SLO panel, e 5% specimen of 20% SLO panel, f 3% specimen of 30% SLO panel and g 5% specimen of 30% SLO panel)

These specimens also exhibited blistering of coatings at defected area indicating permeation of aggressive species toward the metal surface through crack, whereas 3 and 5% specimen of 20% PF-SLO and 30% PF-SLO microcapsules were found to be effective to decrease in corrosion and blistering even in 240 h of immersion as in (Fig. 7). These findings supported addition of soybean oil to linseed oil as healing agent improved healing efficiency of blended oil PF microcapsules along with better protection against corrosion.

6 Conclusion The PF microcapsules containing linseed oil (PF-LO) and soybean oil–linseed oil blends (PF-SLO) were successfully synthesized by in situ polymerization process. The immersion study showed that the addition of less viscous soybean oil to linseed oil enhances self-healing efficiency by filling crack with oil rapidly. Thus, it was proved that the developed PF microcontainers with blended oil combinations were found to be more effective self-healing agents than the microcontainers with linseed oil as anticorrosive coatings. Acknowledgements Financial assistance under Vice Chancellor Research Motivation Scheme (VCRMS) of KBC North Maharashtra University, Jalgaon, is gratefully acknowledged by the authors.

Synergistic Effect of Encapsulated Linseed Oil and Soybean Oil …

137

References 1. Sørensen PA, Kiil S, Dam-Johansen K, Weinell CE (2009) Anticorrosive coatings: a review. J Coat Technol Res 6(2):135–176 2. Alexandra L, Dmitri G, Matthias S, Helmuth M, Dmitry S (2012) A new approach towards active self healing coatings exploitation of microgels. Soft Matt 8:10837–10844 3. Vale´ rie Sauvant M, Serge G, Jean K (2008) Self-healing coatings: an alternative route for anticorrosion protection. Prog Org Coat 63:307–315 4. Huige W, Yiran W, Jiang G, Nancy ZS, Dawei J, Xi Z, Xingru Y, Jiahua Z, Qiang W, Lu S, Hongfei L, Suying W, Zhanhu GJ (2015) Advanced micro/nanocapsules for self-healing smart anticorrosion coatings. Mater Chem A 3:469–480 5. Dmitry GS, Mikhail Z, Helmuth M (2006) Feedback active coatings based on incorporated nanocontainers. J Mater Chem 16:4561–4566 6. Ghosh SK (2009) Self-healing materials: fundamentals, design strategies and applications. In: Ghosh SK (ed) WILEY-VCH Verlag Gmbh & Co. Kgaa, Weinheim, ISBN: 978-3-527-31829-2 7. Suryanarayana C, Chowdoji Rao K, Dhirendra K (2008) Preparation and characterization of microcapsules containing linseed oil and its use in self-healing coatings. Prog Org Coat 63:72–78 8. Jadhav RS, Hundiwale DG, Mahulikar PP (2011) Synthesis and characterization of phenol formaldehyde microcapsules containing linseed oil its use in epoxy for self-healing and anticorrosive coatings. J Appl Poly Sci 119:2911–2916 9. Marathe RJ, Chaudhari ABA, Hedaoo RK, Daewon S, Chaudhari VR, Gite VV (2015) Urea formaldehyde (uf) microcapsules loaded with corrosion inhibitor for enhancing the anti-corrosive property of acrylic-based multifunctional PU coatings. RSC Adv 5:15539–1554 10. Nesterova T, Dam-Johansen K, Pedersen TL, Kiil S (2012) Microcapsule-based self-healing anticorrosive coatings: capsule size, coating formulation, and exposure testing. Prog Org Coat 75:309–318 11. Deligny P, Tuck N (2000) In: Oldring PKT (ed) Resins for surface coatings volume II (2nd edn) Alkyds & Polyesters. Wiley, pp 34–35 12. Shisode PS, Patil CB, Mahulikar PP (2021) Evaluation of coactive influence of oil based selfhealant in functional coatings. J Adhes Sci Tech. https://doi.org/10.1080/01694243.2021.198 4073 13. Bagle AV, Jadhav RS, Gite VV, Hundiwale DG, Mahulikar PP (2013) Controlled released study of phenol formaldehyde microcapsules containing neem oil as an insecticide. Int J Polym Mate Polym Biomate 62:421–425 14. Jadhav RS, Mane V, Bagle AV, Hundiwale DG, Mahulikar PP, Waghoo G (2013) Synthesis of multicore phenol formaldehyde microcapsules and their application in polyurethane paint formulation for self-healing anticorrosive coating. Int J Ind Chem 4(31):1–9 15. Shisode PS, Patil CB, Mahulikar PP (2018) Preparation and characterization of microcapsules containing soybean oil and their application in self-healing anticorrosive coatings. Polym Plast Tech Engg 57(13):1334–1343

Cost-Effective Synthesis of Hydroxyapatite from Waste Egg Shells and Clam Shells Anjali Shibu, Sainul Abidh, P. V. Dennymol, and Tresa Sunitha George

1 Introduction Hydroxyapatite (HA) is a vital inorganic component of natural teeth and bone [1]. Synthetic HA is highly biocompatible, and it has many of the properties of natural bone. It is used as an auxiliary material for bone repair and also in orthopedic repair in dentistry. Hydroxyapatite is non-inflammatory in nature and does not produce any irritating and immunological response. Scaffolds of HA provide the needed support as synthetic extracellular matrices. Biodegradable scaffolds act as the temporary template and repair the lost bone or defective area by developing newer tissues on it. Even though, its osteogenesis effects vary according to its size, crystallinity, morphology, calcium phosphate ratio and some other factors. So, methods used for its synthesis and sources are being improved continuously to isolate synthetic components with similar properties of HA in natural bone tissues. Several research works have been reported on attempts to synthesize materials of similar chemical nature to HA for prosthesis and implant purposes. Biphasic HA was developed as a successful bone substitute in dental implant treatment by Yamaguchi et al. [2]. Dental inserts based on the combination of HA, gelatin and acrylic acid were developed by Sharma et al. [3]. Porous microspheres in HA can be used as tumor drug carriers with good biocompatibility and pH response. It is also used in detection of tumors and in other medical fields. A combination of HA with polymers can be used as bone implants which could overcome the brittle and uncontrolled degradation nature of HA [4]. Apart from bone implants, HA is a proper material as drug carriers due to its biocompatibility and biodegradability [5, 6]. Due to its strong affinity toward heavy metal ions, it is also used as eco-friendly adsorbent material. A. Shibu · S. Abidh · T. S. George (B) Department of Chemistry, St. Paul’s College, Kalamassery, India e-mail: [email protected] P. V. Dennymol Thiagarajar Polytechnic College, Alagappanagar, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_13

139

140

A. Shibu et al.

HA synthesized using chemical reagents cannot completely mimic natural one due to its absence of elements like sodium, aluminum, magnesium which are present in human bone. This can be overcome by utilizing naturally available sources. Isolation of HA from natural sources is cost-effective [7] and has environmental benefits too. The osteo conductivity of HA synthesized from natural resources is found to be greater. Many methods are available for synthesis of HA like sol–gel, precipitation, hydrothermal. Some drawbacks of these approaches are limited yield, high-cost precursors, complex procedures, etc. Chemical precipitation is the most prominent method to isolate HA [8–16] which involves simple experimental steps ensuring high purity and yield. Consumption of energy and temperature required is low resulting in HA with good nanophase particle size control, porous size control and above all large-scale production. India ranks third in egg production in the world. Egg shell is utilized as source of calcium due to its easy availability in India. The selection of egg shell as a source of calcium is due to abundant availability of egg shells in India. The egg shell constitutes the 11% of the total weight of the egg which is useless after the utilization of eggs and egg derivatives. The use of egg shells to generate HA will reduce the pollution and the subsequent conversion of the waste egg shells into a highly valuable product. Egg shells are basically composed of calcium phosphate (1%), magnesium carbonate (1%), magnesium carbonate (1%), organic matter (4%) and calcium carbonate (94%) [17, 18]. In India, annual production of clam is about 75,000 tons which is about 74%. So, the conversion of waste clam shells into HA is advantageous since they are easily available and cheap [19]. Conversion of waste clamp shells into biocompatible materials will also be an added benefit in conservation of environment. Clam shells contains 99% calcium carbonate, and the use of the same is a sustainable way for its disposal. So, the present work aims at cost-effective synthesis of HA using natural materials such as waste egg shells and clam shells (Fig. 1) as calcium precursors which are easily available.

Fig. 1 Waste egg shells and clam shells

Cost-Effective Synthesis of Hydroxyapatite from Waste Egg …

141

2 Materials and Methods The orthophosphoric acid and ammonium hydroxide (65%) are purchased from Merck Mumbai, India. Waste egg shells collected from local catering units in Kalamassery were cleaned thoroughly and boiled in deionized water for 30 min. Calcination of the powdered egg shell was done at 900 °C for 2 h in a muffle furnace. The egg shell is converted into calcium oxide, liberating carbon dioxide at 850 °C. Required amount of calcined egg shell powder was added into a beaker and dispersed in hot water. Calcium oxide was converted to calcium hydroxide. Ammonia (1:1) solution was added dropwise to control the pH 10 to 11. To this hot solution, orthophosphoric acid is added dropwise with continuous stirring. White-colored gelatinous precipitate of HA was observed. Ca (OH)2 was reacted with phosphoric acid in ammoniacal medium to form HA according to the equation, 10Ca(O H )2 + 6H3 P O4 → Ca10 (P O4 )6 (O H )2 + 18H2 O The stirring of solution was continued for another 1 h and kept it for aging for next 24 h. The obtained precipitate was filtered, washed and kept for vacuum drying at 65 °C for 36 h. It was then heated to 900 °C each for 2 h. The same procedure was repeated with clam shells collected from local fishing units in Kalamassery.

3 Characterization of Hydroxyapatite 3.1 Fourier Transform Infrared Spectroscopy Thermo Nicolet FTIR Spectrometer Model Avatar 370 was utilized to study and confirm the nature of the samples by using KBr pellet technique. The FTIR spectrum was scanned from 4000 to 400 cm−1 .

3.2 X-ray Diffraction Analysis HA samples were investigated using Bruker D8 advanced model X-ray diffractograms (XRD) to understand the crystallographic phases employing Cu-Kα radiation (λ = 1.54 A0). The patterns of XRD were taken in the 2θ range of 0–700 with a 0.020 step size using 40 kV tube voltage and of 35 mA tube current. The sample crystalline size was identified by Debye-Scherrer formula D = 0.9 λ/β Cos θ where. D = mean grain size, β = full width at half maximum (FWHM), λ = diffraction wavelength (0.154 nm) and. θ = diffraction angle.

142

A. Shibu et al.

3.3 Thermogravimetric Analysis Thermogravimetric analysis is for assessing the thermal stability of materials. Thermograms provide information about the decomposition temperatures of various materials and their thermal stability. TGA Q50 (TA Instrument) was used to perform TGA at a heating rate of 20 ºC with 6–7 mg of the sample in the nitrogen environment from room temperature to 1000 ºC. The mass of the sample is observed as a function of temperature with the aid of a computer-operated temperature program. The analysis of the DTG and TGA curves were performed using TA Instrument’s Universal Analysis 2000 software version 3.38.

3.4 Scanning Electron Microscopy Morphology of HA samples was investigated using (JEOL JSM 6390 L V) scanning electron microscope (SEM). The conductivity of samples was assured by sputtering of gold prior to electron microscopy.

4 Result and Discussion 4.1 Fourier Transform Infrared Spectroscopy Figures 2a and b represent the FTIR spectra of the hydroxyapatite powder from egg shell and clam shell. Peaks representing to (PO4 )3− and OH groups of HA are visible in the spectrum. The IR spectra showed typical HA absorption bands at about 610 cm−1 and 3573 cm−1 indicating the vibrational and stretching modes, respectively, of the hydroxyl group in HA. The bands at 1628.02 cm−1 and 3440.48 cm−1 correspond to bending modes of hydroxyl groups in the absorbed water in the sample. Absorption peaks visible in the range of 1101–1094 cm−1 (‫ע‬3), 1034-1036 cm−1 (‫ע‬3), 960-962 cm−1 (‫ע‬1) and 561 cm−1 (‫ע‬4), 471 cm−1 (‫ע‬2) direct the presence of (PO4)3− groups in the HA. Band of 1900 cm−1 to 1200 cm−1 is the stretching mode of phosphate. Peak at 874.46 cm−1 and 568.02 cm−1 indicates the stretching and bending modes of PO4 3− , respectively. In Fig. 2b, broad band from 2500 cm−1 to 3300 cm−1 shows OH functional group. Wave number 1420 cm−1 to 1050 cm−1 denotes OH in plane variable position. The peak at 874.46 cm−1 and 1460.18 cm−1 indicates vibration mode of CO3 2− ion [20, 21]. The observed infrared modes of HA vibrations are given in Table 1.

Cost-Effective Synthesis of Hydroxyapatite from Waste Egg …

143

Fig. 2 FTIR spectra of HA from a Egg shell and b Clam shell Table 1 Infrared modes of HA vibrations

Characteristic frequencies

Vibrational frequencies ‫ע‬, cm−1

PO4 bending (‫ע‬4 )

600

OH structural

630

CO3 group (‫ע‬3)

875

PO4 tension (‫ע‬1)

961

PO4 bending (‫ע‬3)

1021

PO4 bending (‫ע‬3)

1090

CO3 group (‫ע‬3)

1429

OH structural

3573

144

A. Shibu et al.

Fig. 3 XRD of HA from a Egg shell and b Clam shell

4.2 X-ray Diffraction (XRD) Analysis Figure 3 shows the XRD of HA at room temperature. The intense peaks observed in the 2θ range of 20–60 are indicative of the hexagonal apatite phase (JCPDS 090432). The major diffraction peaks are observed at 2 theta values such as 39.86, 32.54, 32.19, 31.80 and 25.87 with (h k l) indices plane of (310), (202), (300), (112), (211) and (002),respectively [22]. A high-intensity peak observed from (211) plane indicates the formation of hydroxyapatite. All the observed diffraction peaks are well agreed with the standard value of HAP (JCPDS File no. 09-0432). All the peaks in the XRD patterns are not resolved, but no other impurities are observed.

4.3 Thermogravimetric Analysis The TGA curves for the synthesized HA powder from egg shells are illustrated in Fig. 4. There are three regions of interest in the following thermograms. The first endothermic region from 50 to 200 °C is due to the removal of physically adsorbed water molecules of HA powder. A relatively pronounced weight loss occurs at this region. The decomposition between 200 and 600 °C corresponds to the decomposition of HPO4 2− into P2 O7 4− and H2 O. At this temperature, interstitial water will also be removed [23]. Beyond this temperature, the reaction P2 O7 4− + 2OH− →2PO4 3− + H2 O may occur. Decomposition at this range was small when compared with that occurred at low temperature range. This may be due to the loss of interstitial water rather than to the thermal degradation.

Cost-Effective Synthesis of Hydroxyapatite from Waste Egg …

145

Fig. 4 TGA and DTA curves of HA from egg shell

4.4 Morphological Studies SEM images of synthesized HA powder from egg shells (a, b) and clam shells (c, d) were shown in Fig. 5. It is obvious from the figure that spherical-shaped HA particles were agglomerated resulting in irregular size and shape with pores inside. These pores help in the growth of tissues on implants, when they are used inside the body as a biomaterial.

5 Conclusion HA samples based on egg shells and clam shells as calcium precursor were synthesized successfully using chemical precipitation method. XRD result revealed crystallinity of HA powder, and FTIR analysis shows phase purity of HA powder. Also, the X-ray diffraction patterns, TGA and characterization with FTIR are matched with standard HA. The result shows that both egg shell and sea clam shell can be used as a recycling material for isolating HA powder. This can also help in waste management, thus, keeping environment clean.

146

A. Shibu et al.

Fig. 5 SEM images of synthesized HA powder from (a, b) Egg shells and (c, d) Clam shells

References 1. Mohd Pu’ad NAS, Abdul Haq RH, Mohd Noh H, Abdullah HZ (2020) Synthesis method of hydroxyapatite: a review. Mat Today: Proc 29:233–239 2. Yamaguchi Y, Matsuno T, Miyazawa A, Hashimoto Y, Satomi T (2021) Bioactivity evaluation of biphasic hydroxyapatite bone substitutes immersed and grown with supersaturated calcium phosphate solution. Materials 14(18):5143 3. Kashma S, Shreya S, Sonia T, Madhulika B, Vijay K, Vishal S (2020) Nanohydroxyapatite-, gelatin-, and acrylic acid-based novel dental restorative material. ACS Omega 5(43):27886– 27895 4. Du M, Chen J, Liu K, Xing H, Song C (2021) Recent advances in biomedical engineering of nano-hydroxyapatite including dentistry, cancer treatment and bone repair. Comp Part B: Eng 215:108790 5. Wu S-C, Hsu H-C, Hsu S-K, Chang Y-C, Ho W-F (2016) Synthesis of hydroxyapatite from eggshell powders through ball milling and heat treatment. J Asian Ceram Soc 4(1):85–89 6. Abdulrahman I, Tijani HI, Mohammed BA, Saidu H, Yusuf H, Ndejiko Jibrin M, Mohammed S (2014) From garbage to biomaterials: an overview on egg shell based hydroxyapatite. J Mat 1–6

Cost-Effective Synthesis of Hydroxyapatite from Waste Egg …

147

7. Khoo W, Nor FM, Ardhyananta H, Kurniawan D (2015) Preparation of natural hydroxyapatite from bovine femur bones using calcination at various temperatures. Procedia Manufact 2:196– 201 8. Kalita SJ, Bhardwaj A, Bhatt HA (2007) Nanocrystalline calcium phosphate ceramics in biomedical engineering. Mater Sci Eng C Mat Biol Appl 27(3):441–449 9. Ma G (2019) Three common preparation methods of hydroxyapatite. In: IOP conference series: materials science and engineering, vol 688, p 033057 10. Cox SC, Jamshidi P, Grover LM, Mallick KK (2014) Low temperature aqueous precipitation of needle-like nanophase hydroxyapatite. J Mat Sci Mat Med 25(1):37–46 11. Kumar RR, Prakash KH, Yennie K, Cheang P, Khor KA (2005) Synthesis and characterisation of hydroxyapatite nano-rods/whiskers. Key Eng Mat 284–286:59–62 12. Liu F, Wang F, Shimizu T, Igarashi K, Zhao L (2006) Hydroxyapatite formation on oxide films containing Ca and P by hydrothermal treatment. Ceramics Int 32(5):527–531 13. Wu S-C, Tsou H-K, Hsu H-C, Hsu S-K, Liou S-P, Ho W-F (2013) A hydrothermal synthesis of eggshell and fruit waste extract to produce nanosized hydroxyapatite. Ceramics Int 39(7):8183– 8188 14. Rhee S-H (2002) Synthesis of hydroxyapatite via mechanochemical treatment. Biomaterials 23(4):1147–1152 15. Wu S-C, Hsu H-C, Wu Y-N, Ho W-F (2011) Hydroxyapatite synthesized from oyster shell powders by ball milling and heat treatment. Mat Charact 62(12):1180–1187 16. Mori K, Yamaguchi K, Hara T, Mizugaki T, Ebitani K, Kaneda K (2002) Controlled synthesis of hydroxyapatite-supported palladium complexes as highly efficient heterogeneous catalysts. J Am Chem Soc 124(39):11572–11573 17. Bernalte E, Kamieniak J, Randviir EP, Bernalte-García Á, Banks CE (2019) The preparation of hydroxyapatite from unrefined calcite residues and its application for lead removal from aqueous solutions. RSC Adv 9(7):4054–4062 18. Fitriyana DF, Ismail R, Santosa YI, Nugroho S, Hakim AJ, Syahreza Al Mulqi M (2019) Hydroxyapatite synthesis from clam shell using hydrothermal method : a review. In: 2019 International biomedical instrumentation and technology conference (IBITeC) ´ 19. Rapacz-Kmita A, Paluszkiewicz C, Slósarczyk A, Paszkiewicz Z (2005) FTIR and XRD investigations on the thermal stability of hydroxyapatite during hot pressing and pressureless sintering processes. J Mol Struct 744–747 20. Ooi CY, Hamdi M, Ramesh S (2007) Properties of hydroxyapatite produced by annealing of bovine bone. Ceram Int 33(7):1171–1177 21. Wei M, Evans JH, Bostrom T, Grøndahl L (2003) J Mater Sci: Mater Med 14(4):311–320 22. Ten Huisen KS, Martin RI, Klimkiewicz M, Brown PW (1995) Formation and properties of a synthetic bone composite: hydroxyapatite-collagen. J Bio Mat Res 29(7):803–810 23. Zec S, Miljevi´c N, Milonjic S (2001) The effect of temperature on the properties of hydroxyapatite precipitated from calcium hydroxide and phosphoric acid. Thermochim Acta 374(1):13–22

Neuroprotective Potential of Ayurvedic Herbal Extracts: A Promising Avenue in the Therapeutic Management of Alzheimer Disease Nidhi Gupta, Ritu Verma, Alka Madaan, Kriti Soni, Anu T. Singh, Manu Jaggi, Pallavi Kushwaha, and Surinder P. Singh

1 Introduction Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases affecting a significant number of aging populations worldwide [1]. In India, an estimated 3.7 million elderly people have dementia, and the prevalence is expected to increase two-fold by 2030 and threefold by 2050 [2]. AD is characterized by progressive irreversible cognitive impairment, memory loss and personality changes, finally culminating into severe morbidity and complete dependency on others. The underlying pathophysiology of AD is considered to be the presence of senile plaques (SPs) in the hippocampus. These SPs are formed by the β-amyloid (Aβ) proteins and neurofibrillary tangles (NFTs) composed of phosphorylated tau protein. The amyloid cascade hypothesis and the tau hyperphosphorylation hypothesis are the most accepted underlying pathophysiological processes explaining the occurrence of AD. There are certain new insights into the pathogenesis, but a definitive cause is yet to be discovered [3]. Despite extensive research efforts, the existing treatment modalities of AD are only symptomatic. A definitive treatment for the disease remains elusive. The available treatment in the contemporary system of medicine mainly works by improving the cognitive functions of patients. These are limited to the acetylcholinesterase inhibitors (AChEI) and glutamate modulators [4]. These medications, however, fail in halting the disease progression [5]. The drugs targeting the Aβ and tau proteins were either found ineffective or had severe adverse effects. The N. Gupta · R. Verma (B) · A. Madaan · K. Soni · A. T. Singh · M. Jaggi Dabur Research Foundation, 22, Site 4, Sahibabad 201010, India e-mail: [email protected] N. Gupta · P. Kushwaha (B) · S. P. Singh CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 11012, India e-mail: [email protected] Academy of Scientific and Innovative Research (AcSIR), CSIR-HRDC Campus, Ghaziabad 201002, Uttar Pradesh, India © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_14

149

150

N. Gupta et al.

outcomes of the available FDA-approved drugs for controlling the symptoms of AD are often unsatisfactory. Thus, there is a high demand for identifying effective drug molecules or systems for managing AD. To this end, the system of ayurvedic herbal medicines may present as a promising avenue using traditional nootropic herbs for long-lasting and irreversible relief from the disease with reduced side effects. As per Ayurveda, the samprapti (pathophysiology) of AD is vitiation of Vata in the tissues of the body which affects the brain cells adversely. Ayurvedic treatment system works on the balance of three manasik gunas, i.e., satvik, rajasik and tamsik, which get distributed and cause an imbalance of mental faculties. Ayurveda considers three aspects of mental abilities, i.e., Dhi (the process of acquisition/learning), Dhuti (the process of retention) and Smriti (the process of recall), which have been described in the contemporary system of AD pathology as a dysfunction in the process of acquisition/learning, retention or recall and named as dementia [6]. The β-amyloid (Aβ) toxicity is mediated by several mechanisms including oxidative stress, mitochondrial diffusion, alterations in membrane permeability, inflammation and synaptic dysfunction. Clinical trials of many herbal extracts have shown promising results in the management of AD because of their anti-inflammatory and antioxidants properties [7, 8]. Herein, we have assessed the neuroprotective ability of five traditional ayurvedic herbal extracts, namely tulsi (Ocimum sanctum Linn), gotucola (Centella asiatica), brahmi (Bacopa monnieri), curcumin (Curcuma longa) and rosemary (Rosmarinus officianalis). The neuroprotective effect of the selected herbal extract has been evaluated on SH-SY-5Y neuroblastoma cell lines.

2 Materials and Methods 2.1 Chemicals Dulbecco’s modified eagle medium (DMEM), 3-(4, 5-dimethythiazol-2-yl)-2, 5diphenyl tetrazolium bromide (MTT) and MPP (1-methyl-4-phenylpyridinium)+ iodide were procured from Sigma-Aldrich. Ham’s (F12) and fetal bovine serum (FBS) were purchased from Gibco BRL (Gaithersburg, MD, USA). Dimethylsulphoxide (DMSO) was procured from Rankem. Ethylenediaminetetraacetic acid (disodium salt) (EDTA) was from Titan Biotech. Penicillin streptomycin (antibiotic) was purchased from Himedia. All other chemicals were analytical grade and obtained from either Sigma or Merck.

Neuroprotective Potential of Ayurvedic Herbal Extracts …

151

2.2 Herbal Extracts Herbal extracts powder of gotucola (Centella asiatica extract), brahmi (Bacopa monnieri extract), curcumin (Curcuma longa extract) were procured from Herbo Nutra (Natural Ingredients Solutions Provider, Greater Noida, U.P, 201308, India). Rosemary (Rosmarinus officianalis) was procured from Shivorganics (Mayur Vihar Phase-I Delhi, 110091, India), and tulsi (Ocimum sanctum Linn) was procured from Northern Aromatics Limited, New Delhi, 110001, India.

2.3 Preparation of Herbal Extracts Dilution Based on the solubility of herbs, stocks of gotucola (Centella asiatica) 10 mg/mL, brahmi (Bacopa monnieri) 10 mg/mL and curcumin (Curcuma longa) 25 mg/mL were prepared in ethanol: H2 O (1:1). Stocks of tulsi (Ocimum sanctum Linn) and rosemary (Rosmarinus officianalis) were prepared in 100% ethanol. These herbal extracts stocks were then diluted to a concentration up to 0.01 μg/mL in serum-free (SFM) Dulbecco’s modified eagle medium (DMEM + Ham’s F-12; Sigma (w/v) solution. As a reference control, Galantamine (0.1–20 μM) was used, the drug which has been approved by the Food and Drug Administration (FDA) as safe and effective for the treatment of mild to moderate dementia.

2.4 Cell Culture The cell culture model of Alzheimer, i.e., SH-SY-5Y cell lines, was purchased from National Centre for Cell Science (NCCS), Pune. The received cells were washed with sterile 1X phosphate-buffered saline (PBS) before trypsinization using 0.2% (w/v) trypsin and then incubated at 37 °C under 5% CO2 with 100% humidity in its compatible culture medium, i.e., DMEM + Ham’s F-12. The culture medium used was supplemented with 10% fetal bovine serum (FBS) and antibiotics (1% Antibiotic–Antimycotic and 0.1% Tetracycline). When the cells reached about 80% confluency, they were trypsinized and transferred to new culture flasks. After obtaining sufficient cell density for experimentation, the cells were trypsinized, counted and plated in 96-well culture plates of cell density 25,000 cells per well. The 96-well culture plates containing 180 μl of cell suspension in each well were incubated for 24 hours (h) at 37 °C under 5% CO2 to obtain a single-layer culture of definite cell density. After 24 h of incubation, 20 μl from the prepared herbals extracts solution of different concentrations along with the controls (positive and negative) was added into the well. The experiments were repeated in triplicate. After 24 h of treatment, cells were exposed to neurotoxin MPP+ iodide of 1 mM

152

N. Gupta et al.

(MPP+) for 24 h. After 24 h of neurotoxin addition, the cell restoration by herbal extracts with respect to controls was evaluated by performing an MTT assay.

3 MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] Assay Twenty microliter of MTT reagent (5 mg/mL) was added to each well containing the herbal extracts and controls with culture medium. The cells were incubated for 3 h at 37 °C in the CO2 incubator. After incubation, MTT solution was then dispensed out and 150 μl of dimethylsulphoxide (DMSO) was added. The plates were placed on a shaker to solubilize the formations of purple crystal formazan [9]. The absorbance was measured using a microplate reader at a wavelength of 540 nm (multimode BioTek reader, serial no: 253559; SIAFRT/SYNERGY HT, Medispec India Limited, India). The results were used to calculate the percentage cell restoration after inducing neurotoxic damage with respect to controls. The graph was constructed of cell protection percentage against extract concentrations (Fig. 1).

4 Results and Discussion Traditional herbal extracts in the ayurvedic system have garnered increasing recognition in recent years as dietary supplements and therapeutic agents in the treatment of various neurodegenerative disorders and other diseases [8]. Inflammatory damage and oxidative stress have been the primary cause of the pathogenesis of neurodegenerative diseases. Oxidative stress, one of the earliest events of AD, is an important factor for the onset, progression and pathogenesis of the disease [10]. Human dopaminergic SH-SY-5Y cell lines are being considered to possess many of the qualities of human neurons and serve as a well-established neuronal disorder model because they possess many characteristics of dopaminergic neurons [11]. MPP+-induced cell death has been used as a neurodegeneration model both in vitro and in vivo to study the neuroprotective efficacy of therapeutic agents [11, 12]. In vitro study, intracellular MPP+ can be taken up by cells and concentrated within the mitochondria where it blocks complex I of the electron transport chain. This, in turn, decreases the production of ATP and is believed to increase the formation of ROS, leading to the death of the neurons in substantia nigra pars compacta [13, 14]. In the present study, SH-SY-5Y cells treated with five different traditional herbal extracts, i.e., tulsi (Ocimum sanctum Linn), gotucola (Centella asiatica) brahmi (Bacopa monnieri), curcumin (Curcuma longa) and rosemary (Rosmarinus officianalis), have

Neuroprotective Potential of Ayurvedic Herbal Extracts …

153

(a)

CONTROL

(c)

100

50

100

50

+ PP

MPP+ (1m M)

100

150

Ce ll Prote c on(%)

50

100

50

m (1

C

PP M

0 10

1

) M

l tro on

1

1

10 0

m (1 + PP M

0.

) M

l ro nt Co

Conc. of Curcum a longa (ug/ml)

0. 1

0

+

Ce ll Pr ote c on(%)

(e)

150

0

Conc. of Centella asia ca (ug/m l) MPP+ (1m M)

MPP+ (1m M)

(f)

10 0

Co nt M

+ PP

M

Conc. of Bacopa m onnieri (ug/m l)

MPP+ (1m M)

(d)

10

) ro l

20

10

5

1

0.

1

) M

l

m

ro

(1

Co nt

Conc. of Galantam ine (uM)

1

0

0

M

Cell Protec on(%)

150

Cell Protec on(%)

150

(1 m

(b)

Bocopa monneiri + MPP+ (1mM)

MPP+ (1mM)

150 150

Cell Protec on (%)

100

50

0

100

50

MPP+ (1m M)

Conc. of Ocim us sanctum (ug/ml) MPP+ (1m M)

10

1

0. 1

(1 m M ) M PP +

tro l

10

1

0. 1

Conc. of Rosem arinus officinalis (ug/m l)

Co n

n

(1 m M ) M PP +

tr o l

0

Co

Cell Protec on (%)

(g)

154

N. Gupta et al.

Fig. 1 Effect of herbal extracts on the MPP+-induced neurotoxicity in neuroblastoma cell line SHSY-5Y, a morphology of SH-SY-5Y in control (under 40X objective), MPP+-induced damage (under 10X objective) and at a concentration of 100 μg/mL, Bacopa monnieri (brahmi) cell protection against MPP+-induced damage (under 40X objective) and b reference control (galantamine) c Bacopa monnieri (brahmi) d Curcuma longa (curcumin) e Centella asiatica (gotucola) f Rosmarinus officianalis (rosemary) and g Ocimum sanctum Linn (tulsi). Data are expressed as the percentage of cell protection by herbal extracts in MPP+ (1 mM)-induced neuronal damage (*p < 0.05; ANOVA with Dunnett’s test compared to untreated control. Herbal extracts at different concentrations suggest their potential role in the treatment of AD)

been exposed to MPP+ (1 mM) to induce degeneration of neurons (necrosis). Thereafter, the MPP+-exposed cells were identified for their cytoprotective effect via determining the cell viability of neuronal cells (SH-SY-5Y) using MTT assay. After 24 h of treatment of herbal extracts, a significant cell restoration was observed, and only the data for Bacopa monnieri (Brahmi) that has high neuroprotective efficacy are shown in Fig. 1a. The treatment of MPP+-exposed cells with Ocimum sanctum Linn (tulsi), Centella asiatica (gotucola) Curcuma longa (curcumin) and Bacopa monnieri (brahmi) showed significant cell protection at a concentration of 100 μg/mL. On the other hand, treatment with Rosmarinus officianalis (rosemary) had shown significant cell protection at a lower concentration of 10 μg/mL as shown in Fig. 1f, and it acts as more toxic at a concentration of 100 μg/mL. The detailed studies to understand the behavior of rosemary extract against MPP+-exposed SH-SY-5Y cells are in progress and will be published elsewhere. MPP+ induces a cell viability loss up to 64.4% (from 100% in untreated cells). To understand the cytoprotective behavior, Galantamine has been used as reference control (0.1–20 μM) which demonstrates significant (p < 0.001) cytoprotective potential against MPP+-induced cytotoxicity as reflected by an increase in cell viability from 88.9 to 93.8% as shown Fig. 1b. The different herbal extracts tested for cytoprotective efficacy have demonstrated significant (p < 0.001) neuroprotective potential against MPP+-induced cytotoxicity as reflected by an increase in cell restoration, tulsi (61.7–73.5%), gotucola (74.7– 80.8%), brahmi (71.5–97.2%), curcumin (64.9–77.3%) and rosemary (74.0–79.8%) as shown in Fig. 2. Table 1 shows the percentage of cell protection at different concentrations of tulsi (Ocimum sanctum Linn), gotucola (Centella asiatica), curcumin (Curcuma longa), brahmi (Bacopa monnieri) and rosemary (Rosmarinus officianalis) in human dopaminergic SH-SY-5Y cells. The observed significant neuroprotective potential of herbal extracts treatment may be associated with suppression of the MPP+-induced accumulation of ROS [15, 16]. Based on current preliminary results, brahmi, gotucola and rosemary may be considered for a detailed study to establish neuroprotective potential and their possible role in the treatment of AD.

Cell Restoration (%) w.r.t Control

Neuroprotective Potential of Ayurvedic Herbal Extracts …

155

120 100 80 60 40 20 0

Control

MPP+ (1mM)

0.1µg/mL

1µg/mL

10µg/mL

100µg/mL

Concentration of Herbal Extracts MPP+ (1mM)

Control

Tulsi

Gotucola

Curcumin

Brahmi

Rosemary

Fig. 2 Ayurvedic traditional herbal extracts were evaluated for their neuroprotective potential in SH-SY-5Y cells induced with neurotoxin MPP+ (1 mM). The data are expressed in terms of percentage cell restoration by each herbal extract, reflecting their strong potential as a neuroprotectant Table 1 Percentage cell restoration Herbal extracts

Concentration

Untreated MPP+ (1 mM)

MPP+ (1 mM) Tulsi (μg/mL)

Gotukula (μg/mL)

Curcumin (μg/mL)

Brahmi (μg/mL)

Rosemary (μg/mL)

1

Percent viability with resect to control (%)

Percent protection (%)

100.0

100.0

64.4

0.0

61.7

−7.5

10

62.0

−6.9

100

73.5

25.5

0.1

74.7

28.8

1

76.9

35.0

100

80.8

46.1

0.1

64.9

1.3

1

73.1

24.5

100

77.3

36.3

1

71.5

19.9

10

72.2

21.9

100

97.2

92.2

0.1

74.0

26.8

1

76.7

34.6

10

79.8

43.1

156

N. Gupta et al.

5 Conclusion In summary, this study presents, a cell-protective effect of five traditional Indian herbals extracts [tulsi (Ocimum sanctum Linn), gotucola (Centella asiatica), curcumin (Curcuma longa), brahmi (Bacopa monnieri) and rosemary (Rosmarinus officianalis)] in neuronal damaged SH-SY-5Y cells. We have successfully demonstrated the neuroprotective action of herbal extracts of tulsi (Ocimum sanctum Linn), gotucola (Centella asiatica), brahmi (Bacopa monnieri), curcumin (Curcuma longa) and rosemary (Rosmarinus officianalis) on SH-SY-5Y cells. The results indicate that the antioxidative and anti-apoptotic properties exhibited by herbal extracts may have a considerable neuroprotective action; however, detailed studies are required. A synergistic combination of herbal extracts may further emerge as a potential therapeutic option for neurodegenerative disease such as AD. Acknowledgements Author thanks to Dr. Alka Madaan (Head of Cell Biology, DRF), Dr. Namita Gupta (Principal Research Scientist, DRF), Dr. Kriti Soni (Head of Department of Formulation, DRF), for providing him intellectual and technical help during the conduct of study. The author declares that there is no conflict of interest.

References 1. Lin Y, Smith A, Aspelund T (2019) Genetic overlap between vascular pathologies and Alzheimer’s dementia and potential causal mechanisms. Alzheimers Dement 15:65–75. https:// doi.org/10.1016/j.jalz.2018.08.002 2. Alzheimer’s Association (2010) Alzheimer’s disease facts and figures. Alzheimer’s Dement 6:158–194. https://doi.org/10.1016/j.jalz.2010.01.009 3. Fan L, Mao C, Hu X, Zhang S, Yang Z, Hu Z, Sun H, Fan Y, Dong Y, Yang J, Shi C, Xu Y (2020) New insights into the pathogenesis of Alzheimer’s disease. Front Neurol 10:1312. https://doi.org/10.3389/fneur.2019.013124 4. Panza F, Lozupone M, Logroscino G, Imbimbo BP (2019) A critical appraisal of amyloid-βtargeting therapies for Alzheimer disease. Nat Rev Neurol 15:73–88. https://doi.org/10.1038/ s41582-018-0116-6 5. Graham WV, Bonito-Oliva A, Sakmar TP (2017) Update on Alzheimer’s disease therapy and prevention strategies. Annu Rev Med 68:413–430. https://doi.org/10.1146/annurev-med-042 915-103753 6. Mehla J, Gupta P, Pahuja M, Diwan D, Diksha D (2020) Indian medicinal herbs and formulations for Alzheimer’s disease, from traditional knowledge to scientific assessment. Brain Sci 10;10(12):964. https://doi.org/10.3390/brainsci10120964 7. Limpeanchob N, Jaipan S, Rattanakaruna S, Phrompittayarat W, Ingkaninan K (2008) Neuroprotective effect of Bacopa monnieri on beta-amyloid-induced cell death in primary cortical culture. J Ethnopharmacol 120:112–117. https://doi.org/10.1016/j.jep.2008.07.039 8. Rao RV, Descamps O, John V, Bredesen DE (2012) Ayurvedic medicinal plants for Alzheimer’s disease: a review. Alzheimers Res Ther 4:22. https://doi.org/10.1186/alzrt125 9. Vajrabhaya L, Korsuwannawong S (2018) Cytotoxicity evaluation of a Thai herb using tetrazolium (MTT) and sulforhodamine B (SRB) assays. J Anal Sci Technol 9(15). https://doi.org/ 10.1186/s40543-018-0146-0

Neuroprotective Potential of Ayurvedic Herbal Extracts …

157

10. Uttara B, Singh A, Zamboni P, Mahajan R (2009) Oxidative stress and neurodegenerative diseases: a review of upstream and downstream antioxidant therapeutic options. Curr Neuropharmacol 7:65–74. https://doi.org/10.2174/157015909787602823 11. Hong-rong X, Lin-sen H, Guo-yi L (2010) SH-SY5Y human neuroblastoma cell line: in vitro cell model of dopaminergic neurons in Parkinson’s disease. Chin Med J (Eng) 123(8):1086– 1092. https://doi.org/10.3760/cma.j.issn.0366-6999.2010.08.021 12. Sang Q, Liu X, Wang L, Qi L, Sun W, Wang W, Sun Y, Zhang H (2018) Curcumin protects an SH-SY5Y cell model of Parkinson’s disease against toxic injury by regulating HSP90. Cell Physiol Biochem 51:681–691. https://doi.org/10.1159/000495326 13. Dias V, Junn E, Mouradian MM (2013) The role of oxidative stress in Parkinson’s disease. J Parkinsons Dis 3(4):461–491 31. https://doi.org/10.3233/JPD-130230 14. Enogieru AB, Omoruyi SI, Ekpo OE (2020) Aqueous leaf extract of Sutherlandia frutescens attenuates ROS-induced apoptosis and loss of mitochondrial membrane potential in MPP+treated SH-SY5Y cells. Trop J Pharm Res 19:549–555. https://doi.org/10.4314/tjpr.v19i3.13 15. Przedborski S, Jackson-Lewis V (1998) Mechanisms of MPTP toxicity. Mov Disord 13(Suppl 1):35–38 (PMID: 9613716) 16. Cassarino DS, Parks JK, Parker WD, Bennett JP (1999) The parkinsonian neurotoxin MPP+ opens the mitochondrial permeability transition pore and releases cytochrome c in isolated mitochondria via an oxidative mechanism. Biochim Biophys Acta BBA Mol Basis Dis 1453:49–62. https://doi.org/10.1016/S0925-4439(98)00083-0

Formaldehyde Gas Sensor Based on MoS2 /RGO 2D/2D Functional Nanocomposites Jyoti Gupta, Prachi Singhal, and Sunita Rattan

1 Introduction The accumulation of carcinogens in atmosphere is the main concern to protect our environment and many related health ailments. Formaldehyde is one of those toxic constituents, and it is considered as Group 1 carcinogen to human lives by the International Agency for Research on Cancer (IARC) [1]. Formaldehyde is being used in processing of many industrial products including biomedical materials, plastics, resins, adhesives, cleaning agents, preservatives in food industry. Further, it is emitted from vehicle emissions, incinerators, etc. [2]. Long-term exposure of even low concentrations of formaldehyde is a critical risk factor to human health as it can trigger damage of lungs, kidneys, and even brain and nervous system. Thus, rapid detection of HCHO at room temperature and at low cost with ease of operation aroused interest in development of efficient gas sensor. Conventional HCHO sensors employing semiconducting metal oxides operate at high temperatures (typically 200–600 °C) [3–6], which add to their cost and reduce their durability. The limitations of high temperature operation have recently motivated researchers to design and fabricate gas sensors which operate at room temperature. 2D nanomaterials with high surface area, excellent electrical properties, high density of active sites, and lower operating temperature make them ideal candidate for chemiresistive gas sensing. Graphene, as an excellent example of 2D material, with very high surface area-to-volume ratio, unique structure, flexibility, and high conducting network makes graphene and graphene derivatives as promising contender to construct flexible and efficient gas sensors. However, poor adsorption of gas molecules on graphene inert surface poses a challenge, which can be counteracted through different strategies including functionalization, doping. One of the J. Gupta · P. Singhal · S. Rattan (B) Amity Institute of Applied Sciences, Amity University Uttar Pradesh, Noida, Uttar Pradesh, India e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022 B. Gupta et al. (eds.), Polymeric Biomaterials and Bioengineering, Lecture Notes in Bioengineering, https://doi.org/10.1007/978-981-19-1084-5_15

159

160

J. Gupta et al.

important strategies could be hybridization of graphene with another potential 2D material, transition metal dichalcogenides (TMDs) such as molybdenum disulphide (MoS2 ), which provides opportunity of controlling and tailoring the sensing performance of the hybrids [7–9]. However, the application of solely MoS2 -based gas sensors is limited due to their sluggish reversibility in sensing and instability issues. Therefore, the combination of RGO and MoS2 provides the synergistic effect to enhance the sensor properties of the synthesized material.

2 Materials and Methods 2.1 Materials Graphite powder, MoS2 , hydrazine hydrate, sodium borohydride, ammonium tetra thiomolybdate (NH4 )2 MOS4 were obtained from Sigma-Aldrich. Dichloromethane was obtained from Kanto chemicals. All chemicals of analytical grade were used in this experiment.

2.2 Synthesis of RGO/MoS2 2D/2D Nanocomposite Initially, graphene oxide was synthesized by modified Hummer’s method from pristine graphite powder as described in our previous research publications [10]. About 100 mg of prepared GO was dissolved in 100 ml of water for preparing RGO. Now, 10 μl of hydrazine hydrate was added into this GO solution and refluxed it for 1 h at 80 °C. After that, 1 mg of NaBH4 (sodium borohydride) was added into this solution and again refluxed it for 36 h at 100 °C and cool down at room temperature. The synthesized material was filtered using Millipore filter paper and washed it with deionized water and dried it. Synthesis of RGO/MoS2 nanocomposite is carried out through microwaveassisted method in which 10 mg of ammonium tetra thiomolybdate (NH4 )2 MOS4 crystals is mixed with 20 ml hydrazine, 10 ml distilled water and 10 mg of RGO. The mixture is subjected to microwave treatment at 800 W for 1 min. After microwave treatment, the product obtained is filtered off, washed several times with isopropanol, and finally air dried. The RGO/MoS2 nanocomposite, thus, obtained is dispersed in dimethyl formamide and spin-coated on glass slide for carrying out electrical and sensing studies. The synthesis strategy for MoS2 /NGP 2D/2D nanocomposites, film formation through spin coating and sensing setup, is represented through Scheme 1.

Formaldehyde Gas Sensor Based on MoS2 /RGO 2D/2D Functional …

161

Scheme 1 The synthesis strategy for RGO/MoS2 nanocomposites

2.3 Film Characterization The microstructure evaluation of RGO/MoS2 nanocomposites was carried out through FTIR and XRD analysis. XRD evaluation is done using Cu-Kα radiation source with 2θ varying from 10° to 60° through XRD, Rigaku SmartLab. FTIR was performed through PerkinElmer Fourier transform spectroscope.

2.4 Electrical and Sensing Evaluation Electrical contacts were made with the help of silver paste and copper wires on the spin-coated RGO/MoS2 nanocomposite film, and electrical and sensing studies were carried out using Keithley electrometer (6517B). Current–voltage (I–V) characteristics of the prepared nanocomposite film were studied within the voltage range of − 1 V to +1 V. All the current and voltage measurements were done at room temperature. The sensing response of RGO/MoS2 nanocomposites toward formaldehyde vapors was measured using conventional resistance measurement method by placing the sensor inside the gas chamber in open environment, where nanocomposite sensor film was exposed to formaldehyde vapors. Figure 4 shows the sensor response exhibited by RGO/MoS2 at room temperature toward formaldehyde vapors. The sensing response of nanocomposite sensor is calculated by

162

J. Gupta et al.

(R/Rbefore ) = ((Rafter − Rbefore )/Rbefore )

(1)

S R(%) = (R/Rbefore ) ∗ 100

(2)

where Rafter and Rbefore are the resistances at any time t after exposure of formaldehyde vapor and the steady state resistance before exposure of formaldehyde vapors. The sensitivity of the nanocomposites to formaldehyde vapor was calculated as S=

S R(%) Concentration

(3)

The sensor response toward formaldehyde vapors was found to be 0.74%. The response and recovery time are taken as the time taken to reach 90% of the total change in resistance during the response and recovery process. The concentration of injected formaldehyde vapors in the chamber was calculated in ppm by C=

22.4ρT Vs ∗ 1000 273M V

(4)

where C is the concentration of gaseous ethanol (ppm), r is the density of liquid formaldehyde (g mL1), T is the testing temperature (K), V s is the volume of liquid formaldehyde (mL), M is the molecular weight of ethanol (g mol1), and V is the volume of the chamber (L). The concentration of injected formaldehyde vapors in the chamber is 1 ppm. The sensitivity is calculated as 0.74%/ppm.

3 Results and Discussion 3.1 Fourier Transform Infrared (FTIR) Studies Figure 1 has represented the FTIR spectra of RGO/MoS2 nanocomposite film. Characteristic peaks at 3440.85 cm−1 , 3046.26 cm −1 , 1770.12 cm−1 , and 1638.55 cm−1 attributed to the O–H stretching band, C–H stretching band of aromatic ring, and carboxylic (C=O) stretching band, respectively. The intensity peak at 803.44 cm−1 represented the peak of RGO, whereas broad peak around 800 cm−1 likely originated from C–O–C bending [11, 12]. The Mo-S stretching band was represented by distinctive peak at 1394.46 cm−1 in synthesized RGO/MoS2 nanocomposite film.

Formaldehyde Gas Sensor Based on MoS2 /RGO 2D/2D Functional …

163

Fig. 1 FTIR of RGO/MoS2 nanocomposite

Fig. 2 XRD of a RGO and b RGO/MoS2 nanocomposite

3.2 X-ray Diffraction (XRD) Studies Figures 2a, b have represented the XRD pattern of simple RGO and RGO/MoS2 2D/2D nanocomposite. respectively. RGO was depicted by a characteristic 2θ peak at 26.5° assigned to (002) crystal plane of RGO. Two distinct peaks at 2θ = 14.5°, 32.4° are assigned to 002, 100 planes of MoS2 .

3.3 I–V Characteristics The I–V characteristic curves for the RGO/MoS2 nanocomposite film were depicted in Fig. 3. The I–V characteristics of the films were evaluated, and the conductivity of the films was found to be in the range ~10−3 to 10−2 .

164

J. Gupta et al.

Fig. 3 Characteristic I–V curve for RGO/MoS2 nanocomposite film

Fig. 4 Sensing response pattern of RGO/MoS2 nanocomposite film toward formaldehyde vapors at room temperature

3.4 Sensing Studies The sensing response characteristic of RGO/MoS2 nanocomposite sensor toward formaldehyde at room temperature was represented in Fig. 4. The sensing pattern of RGO/MoS2 nanocomposite film depicted p-type sensing response toward formaldehyde as shown by increase in resistance on exposure to the formaldehyde vapors (reducing species) and decrease in resistance back to the initial resistance on cutting off the formaldehyde or exposure of the sensor to air. The sensitivity was found to be ~0.74%/ppm at room temperature with excellent reproducibility. Further, sensor showed fast response (4–5 s) and recovery (~35 s) time which cannot be shown either by RGO or by MoS2 alone. The response may be attributed to the high density of exposed active sites, heterojunction effect preventing charge accumulation during interaction, and the conducting network provided by RGO nanosheets. The result indicated the potential action of RGO/MoS2 nanocomposite film as room temperature formaldehyde sensor without use of any other thermal treatment.

Formaldehyde Gas Sensor Based on MoS2 /RGO 2D/2D Functional …

165

4 Conclusion In this present work, RGO/MoS2 binary nanocomposites film were synthesized through microwave-assisted method as potential candidate for chemiresistive formaldehyde vapor sensing. The binary nanocomposite film has shown good sensor response (0.74%) toward formaldehyde vapors with very fast response (5.22 s) and recovery time (15 s) at room temperature in open environment. The binary nanocomposite film had heterojunction at RGO and MoS2 interface due to which electron transfer mechanism becomes fast as compared to individual nanocomposite that was responsible for fast response time as well as good sensing response.

References 1. Noor A, Bohari SS, Kamaruzaman A (2016) Development of formaldehyde biosensor for determination of formalin in fish samples. Biosensors 6(3):32 2. Fang F et al (2015) Hierarchically porous indium oxide nano lamellas with ten-parts-perbillion-level formaldehyde-sensing performance. Sensors Actuators B 206:714–720 3. Güntner AT, Koren V, Chikkadi K, Righttoni M, Pratsinis SE (2016) Highly selective formaldehyde (FA) detection with flame-made gas sensors for indoor air quality monitoring. ACS Sens 1:528–535 4. Xu K, Zeng D, Tian S, Zhang S, Xie C (2014) Enhanced room-temperature NH3 gas sensing by 2D SnS2 with sulfur vacancies synthesized by chemical exfoliation. Sens Actuators B 190:585–592 5. Wang L, Dou H, Li F, Deng J, Lou Z, Zhang T (2013) Controllable and enhanced HCHO sensing performances of different-shelled ZnO hollow microspheres. Sens Actuators B 183:467–473 6. Rao C, Gopalakrishnan K, Maitra U (2015) A comparative study of the potential applications of graphene, MoS2 and other 2D materials in energy devices, sensors and related areas. ACS Appl Mater Interfaces 7:7809–7832 7. Lu JP, Lu JH, Liu HW, Liu B, Gong LL, Tok ES, Loh KP, Sow CH (2015) Facile fabrication of wafer-scale MoS2 neat films with enhanced third-order nonlinear optical performance. Small 11:1792–80 8. Kuru CH, Choi CM, Kargar A, Kim YJ, Liu CH, Yavus Z, Jin S (2015) MoS2 nanosheet–Pd nanoparticle composite for highly sensitive room temperature detection of hydrogen. Adv Sci 2:1500004 9. He QY, Zeng ZY, Yin ZY, Li H, Wu SX, Huang X, Zhang H (2012) Fabrication of flexible MoS2 thin-film transistor arrays for practical gas-sensing applications. Small 8(19):2994–2999 10. Gupta J, Singhal P, Rattan S (2020) Chitosan/nanographiteplatlets (NGP)/tungsten trioxide (WO3 ) nanocomposites for visible light driven photocatalytic applications. In: Jain VK, Rattan S, Verma A (eds) Recent trends in materials and devices, vol 256. Springer Proceedings in Physics, Singapore 11. Du FF, Cao NN et al (2018) PEDOT: PSS/graphene quantum dots films with enhanced thermoelectric properties via strong interfacial interaction and phase separation. Sci Rep 8:6441 12. Faucett AC, Flournoy JN, Mehta JS, Mativetsky JM (2017) Evolution, structure, and electrical performance of voltage-reduced graphene oxide. Flat Chem 1:42–51