Artificial Liver [1st ed.] 9789811559839, 9789811559846

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Artificial Liver Lanjuan Li Editor

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Artificial Liver

Lanjuan Li Editor

Artificial Liver

Editor Lanjuan Li The First Affiliated Hospital Zhejiang University Zhejiang University Hangzhou China

ISBN 978-981-15-5983-9    ISBN 978-981-15-5984-6 (eBook) https://doi.org/10.1007/978-981-15-5984-6 © Springer Nature Singapore Pte Ltd. and Zhejiang University Press 2021 Jointly published with Zhejiang University Press This work is subject to copyright. All rights are reserved by the Publishers, 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 publishers, 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 publishers 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 publishers remain 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

Preface

Liver failure is a critical illness with a high mortality rate, which is a worldwide problem for treatment. An artificial liver is a sort of effective and practical method for the clinical treatment of liver failure, and it can remove various harmful substances and compensate for liver functions in order to improve the internal environment and facilitate cellular regeneration, thus rescuing the patients with liver failure from death. Furthermore, it can also be utilized as a “bridge” before transplant to extend the waiting time for a donor liver for patients with advanced liver failure, improving preoperative conditions and the success rate of liver transplant. In order to popularize the concept of and the treatment technology for artificial livers, we have compiled and published the first monograph, named Artificial Liver, in 2001 in China, which systematically introduced the history and mechanism of artificial livers, non-bioartificial and bioartificial livers, hybrid artificial livers, the prevention and treatment of complications, as well as severe hepatitis, liver failure, and artificial livers in liver transplants. The publication of Artificial Liver has strongly promoted the popularization and generalization of artificial livers in China. In 2012, we revised Artificial Liver to summarize worrisome and key scientific issues in the field of research both at home and abroad, tracking the latest developments to promote basic and clinical studies of artificial livers. Artificial Liver (Second Edition) has become a favorite reference book for a vast number of clinicians and researchers engaged in the field of liver failure in China. With the intensive studies and deep understanding of pathogenesis in liver failure, the concept of diagnosis and treatment has undergone significant changes, and some progress has been made in the field of non-bioartificial, bioartificial, and hybrid artificial livers. In particular, stem cell transplants, liver tissue engineering, and some new technologies have shown a bright future. Therefore, based on Artificial Liver (Second Edition), we have updated the new findings in the field of artificial liver and published the English version of Artificial Liver. This book is divided into 21 chapters, including some new theories and knowledge about molecular biology, proteomics, tissue engineering, and some new methods for artificial liver treatment.

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Although we have spent a lot of time and energy in writing this book, it is likely that some mistakes are inevitable. Therefore, your comment is appreciated so that we can improve our work. Hangzhou, China

Lanjuan Li

Contents

1 Introduction����������������������������������������������������������������������������������������������    1 Xiaoli Liu, Xiaoxi Ouyang, and Lanjuan Li 2 Liver Structure����������������������������������������������������������������������������������������   21 Sainan Zhang, Wenqian Chen, and Chunxia Zhu 3 Liver Function������������������������������������������������������������������������������������������   49 Shaorui Hao 4 Liver Regeneration and Tissue Engineering ����������������������������������������   73 Qian Zhou, Linxiao Fan, and Jun Li 5 Etiology of Liver Injury��������������������������������������������������������������������������   95 Chunlei Chen, Wenrui Wu, and Yongtao Li 6 Pathogenesis of Liver Injury and Hepatic Failure��������������������������������  105 Liang Yu 7 Liver Pathology����������������������������������������������������������������������������������������  167 Jinlin Cheng and Zhaoming Wang 8 Laboratory Evaluation of Liver Failure������������������������������������������������  205 Yu Chen 9 Imaging Examination of Liver Failure��������������������������������������������������  243 Tian’an Jiang, Linya Yu, Yilei Zhao, and Baohua Wang 10 Diagnosis of Liver Failure ����������������������������������������������������������������������  283 Qing Cao and Chengbo Yu 11 Internal Medical Treatment of Liver Failure����������������������������������������  299 Zhengyi Jiang and Jiajia Chen 12 Mechanism for the Functioning of the Artificial Liver������������������������  321 Qiongling Bao, Jing Guo, Yanfei Chen, Fengling Yang, and Lanjuan Li vii

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Contents

13 Non-bioartificial Liver ����������������������������������������������������������������������������  379 Zhongyang Xie, Yalei Zhao, Danhua Zhu, Xiaowei Xu, Qian Yang, and Lanjuan Li 14 Operation and Management of Artificial Liver Support Systems��������������������������������������������������������������������������������������  413 Xiaoqian Zhang and Huafeng Zhang 15 Artificial Liver Support System: Complications and Prevention������������������������������������������������������������������������������������������  441 Xiaowei Xu, Laurencia Violetta, and Zhongyang Xie 16 Efficacy and Its Evaluation of Non-bioartificial Liver ������������������������  461 Zuhong Li and Qi Xia 17 Bio-Artificial Liver����������������������������������������������������������������������������������  479 Yanhong Zhang, Juan Lu, Feiyang Ji, Jie Wang, Xiaoping Pan, and Lanjuan Li 18 Hybrid Artificial Liver����������������������������������������������������������������������������  505 Yimin Zhang, Kaizhou Huang, Danhua Zhu, and Lanjuan Li 19 Cell Transplantation Therapy for Liver Failure ����������������������������������  519 Chenxia Hu, Jiong Yu, Hongcui Cao, and Jun Li 20 Artificial Liver and Liver Transplantation��������������������������������������������  541 Diyu Chen, Tian Shen, and Jian Wu 21 Four Clinical Cases����������������������������������������������������������������������������������  551 Jiajia Chen, Shaorui Hao, Xiaoli Liu, Liang Yu, and Lanjuan Li 22 Prospect����������������������������������������������������������������������������������������������������  561 Weibo Du, Ermei Chen, and Lanjuan Li

Chapter 1

Introduction Xiaoli Liu, Xiaoxi Ouyang, and Lanjuan Li

Liver failure is a clinical syndrome which is defined as severe hepatic derangements resulting from varied insults, such as viruses, drugs, and toxins, leading to coagulation abnormality, jaundice, hepatic encephalopathy, ascites, etc. [1]. Liver failure belongs to the group of diseases that are medical emergencies and for which the effect of conventional medical treatment is not ideal. Its mortality rate is as high as 50–80%, among which the mortality rate of patients with stage IV hepatic encephalopathy even reaches 90–95%. Liver transplant is the standard therapy for patients with liver failure; however, less than 30% of the patients on waiting lists receive a transplant because of the shortage of organ donors [2]. In order to overcome the high mortality rate of liver failure, the artificial liver system (ALS) has attracted increased focus over the last decades. ALS, with the primary goal of detoxifying blood, is widely used in clinics to compensate liver function until the patient’s native liver regenerates, or a liver donor becomes available for transplant. In the past few decades, the ALS has gradually improved. Now, there are mainly three types of the ALS, namely, non-bioartificial liver (NBAL), bioartificial liver (BAL), and hybrid artificial liver (HAL). The application of the ALS for liver failure is an important part of the progress in modern medicine for hepatology, as it is the artificial heart–lung extracorporeal circulation machine and breathing machine developing for cardiac surgery or hemodialysis bringing new opportunities for the treatment of renal failure. The ALS has greatly changed the traditional thought and mode of the treatment of liver failure.

X. Liu · X. Ouyang · L. Li (*) State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China e-mail: [email protected] © Springer Nature Singapore Pte Ltd. and Zhejiang University Press 2021 L. Li (ed.), Artificial Liver, https://doi.org/10.1007/978-981-15-5984-6_1

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1.1  Concept and Classification of Artificial Liver Systems The artificial liver system is a therapeutic means by which an external mechanical, physicochemical, or biological device is used to remove toxic substances from the blood that have been caused by liver failure, to supplement necessary substances such as proteins synthesized by the liver, and to stabilize the internal environment. Then, it temporarily replaces part of the liver functions, until the regeneration of autologous hepatocytes and the recovery of liver function is achieved, so as to promote the survival and recovery of patients with liver failure. For the patients who have poor hepatocyte regeneration, the artificial liver system (ALS) can improve the symptoms and is regarded as a “bridge” to liver transplant. There are three main types of the ALS as follows (Table 1.1): 1. Non-bioartificial liver (NBAL): also called physical-type of artificial liver system, refers to using various mechanical and physicochemical blood purification methods to remove the harmful substances caused by liver failure and temporarily replace the liver function during the treatment. Non-bioartificial liver treats liver failure via methods of plasma exchange (PE), hemofiltration (HF), plasma diafiltration (PDF), hemoperfusion (HP), and albumin dialysis (AD) [3]. The main non-bioartificial liver systems include Li’s non-bioartificial liver system (Li-NBAL), molecular adsorbents recirculating system (MARS™), plasma separation and absorption system (Prometheus™), etc. 2. Bioartificial liver (BAL): refers to the cultivated liver cells in  vitro which are placed in a special bioreactor, in which the blood is introduced by the in vitro perfusion system to complete synthesis and metabolism. It consists of two major components, cell sources and bioreactors. The main bioartificial liver systems under current research are Li’s bioartificial liver (Li-BAL), the Extracorporeal Liver Assist Device (ELAD), the Bioartificial Liver Support System (BLSS) and the Radial Flow Bioreactor (RFB), etc. 3. Hybrid artificial liver (HAL): it refers to the system that combines the advantage of the NBAL and BAL devices; it uses the NBAL to effectively remove toxins and perfuses the patient’s blood with exotic hepatocytes to t­emporarily replace complex functions such as synthesis, detoxification, and biotransformation of the injured liver. The HAL mainly includes liver cells, bioreactor, and in vitro Table 1.1  Classification of artificial liver systems Classification Non-­bioartificial liver Bioartificial liver Hybrid artificial liver

Functions Remove the toxic substances and supplement the beneficial substances such as coagulation factors Detoxification, biosynthesis, and transformation of the liver functions Combine the high efficient detoxification of NBAL and the metabolic function of BAL

Main technologies and devices Li-NBAL, MARS™, Prometheus™ system and bilirubin absorption et al Li-BAL, ELAD, BLSS, and RFB et al Li-HAL, HepatAssist, MELS, and AMC, et al

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plasma exchange/plasma perfusion. Currently, HALs are in the research stage, including Li’s hybrid artificial liver (Li-HAL), the HepatAssist, the Modular Extracorporeal Liver Support (MELS), the Academic Medical Center (AMC) system, etc. At present, the classifications of artificial livers from different specialists are not the same, especially in the specific distinction between BAL and HAL.  Some researchers consider that the HAL which contains activated carbon perfusion as a BAL. However, some researchers consider that the BAL can also be called HAL, because it is not a simple biological component, instead, it places the biological components (hepatocytes) into an artificially synthesized semipermeable membrane to develop the liver function by means of the traditional dialysis devices. In this book, the concept and classification of ALS are described according to the former concepts of NBAL, BAL, and HAL.

1.2  Development of Artificial Liver Systems In 1956, Sorrention demonstrated the detoxification ability of the fresh liver tissue homogenate, and the concept of “artificial liver” was proposed for the first time. Since then, the artificial liver systems have experienced more than half a century of development. Reviewing this history, it can be divided into the following stages:

1.2.1  The 1950s–1960s: The Rise of Artificial Liver Research In the 1950s, most researchers believed that the toxin causing the liver hepatic coma was a kind of dialyzable molecule. Therefore, the early artificial liver devices mainly focused on compensating the detoxification function of liver. For example, Kiley, et al. used hemodialysis to treat patients with hepatic encephalopathy, which efficiently reduced blood ammonia and restored the consciousness of patients (without prolonging patients’ survival time). In 1958, Schechter et al. reported using hemoperfusion with the Dowex50-X8 ion exchange resin for the treatment of hepatic encephalopathy. Over the same period, Kimoto invented the first HAL with complex functions. This device is composed of four cross-connected hemodialyzers connected to the liver of four dogs and is equipped with four ion exchange resins, which can absorb ammonia and correct acid-base balance, thereby reducing blood ammonia and bilirubin. After 55 min of treatment, a patient with stage IV hepatic encephalopathy miraculously woke up. In 1964, Yatzidis developed the technology of hemoperfusion by activated carbon, but the problem of blood cell destruction was not solved. At the same time, the artificial liver system devices of applied biomaterials also began to appear. In 1958, Otto, et al. pioneered the hemoperfusion of extracorporeal

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Table 1.2  Clinical effects of early artificial liver devices Technology Kolff dialysis Dogs liver perfusion Pigs liver perfusion Cadaver liver perfusion Exchange transfusion Cross circulation Plasma exchange Activated carbon perfusion PAN hemodialysis

Researcher Kiley Kimoto Eiseman Sen

Report time 1958 1959 1965 1966

Encephalopathy improvement (case number) 4/5 1/2 8/8 4/5

Survival (case number) 0/5 0/2 0/8 1/5

Trey

1966

7/7

5/7

Burnell Sabin Gazzard

1967 1968 1974

2/3 3/3 11/22

1/3 0/3 10/22

Opolon

1976

13/24

5/24

liver perfusion (ECLP) in animals. Subsequently, Eiseman and Abonna improved the device. At that time, the method was supposed to replace the functions of the liver quickly and effectively. However, it was challenging owing to some issues, such as complicated equipment, immunoreaction, etc. In 1959, Nose designed the device which placed the production of dog liver, such as liver tissue homogenate, fresh liver slices, or frozen dried particles of liver tissue, into the bioreactor and perfused by means of a geltype semipermeable membrane. In a limited number of clinical applications, this device was able to maintain the blood glucose concentration and eliminate the excess lactate and ammonia in the serum, which made it become a rudiment of a modern BAL. However, how to maintain the activity of liver tissue was the biggest problem of this device. It could be seen that the artificial liver system devices at this stage were various, including the non-biotype, the biotype, and even hybrid artificial liver devices. However, generally speaking, the research on artificial liver system was still in the exploratory stage, and there were only a few clinical applications. Table 1.2 lists some clinical effects of early artificial liver devices, which indicate that the artificial liver system is feasible in methodology (After treatment, patients’ neurological or hepatic encephalopathy symptoms usually improve temporarily), but there is no significant change in the patient’s survival rate [4].

1.2.2  T  he 1970s: The Technology of Hemopurification Encouraged the Development of NBAL The development of the artificial liver system is the result of the overall development of medicine and multidisciplinary collaboration. In the 1970s, with the development of membrane technology, the traditional hemodialysis, hemofiltration, and hemoperfusion were improved. The appearance of polyacrylonitrile (PAN) led to the improved effects of hemodialysis. It was able to eliminate the substances with a molecular weight of 1500–15,000 Da, which were close to the adsorption range of

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the activated carbon perfusion, and the scavenging ability of blood ammonia and aromatic amino acid was better than that of the activated carbon perfusion. In 1976, Opolon et al. used a copper imitation membrane and PAN membrane to contrastively study the hemodialysis of pig model with fulminant liver failure. It was found that PAN membrane hemodialysis had good effects on the recovery of the animal consciousness and the improvement of the electroencephalogram. The main progress of the adsorption type of artificial liver is the improvement of the compatibility of the adsorbent and the adsorption capacity. In 1972, Mingrui Zhang reported of using the encapsulated activated carbon to perfuse, which could wake up the coma patients caused by acute alcoholic hepatitis. The usage of microcapsule membrane divided apart from the activated carbon from the visible component of blood, so as to prevent the destruction of white blood cells and platelets, as well as the release of activated carbon particles, which led to the clinical application of the activated carbon hemoperfusion. During that period, Seglen et al. studied the hepatocyte isolation profoundly, and a two-step perfusion method was developed. This made it possible to prepare high yields of viable hepatocyte suspensions and it also made important contributions to the next stage of artificial liver research based on the hepatocytes culture. However, after a week of culture in vitro, the biological function and activity of hepatocytes were greatly reduced, which limited many experimental studies.

1.2.3  T  he 1980s–1990s: The Continuous and in-Depth Study of NBAL and the Rise of BAL Research Some new hemopurification methods achieved great progress. Hemodiabsorption refers to the suspension of tiny adsorbent particles in dialysate [5]. Among which, the adsorbent is able to absorb the toxic substances in the dialysate to make hemodialysis more effective. Hemodiafiltration is a method with the combination of hemofiltration and hemodialysis [6]. It combines the advantages of diffusion and convection and leads to a higher removal rate of the medium molecular substance. Plasma exchange is a hemopurification method which separates plasma from blood through a plasma separator and discards the plasma; in the meanwhile, the same amount of fresh frozen plasma and/or albumin solution is supplemented. Several years later, new development was obtained based on plasma separation. After separation, instead of being discarded, the plasma flows through the perfusion device which includes different kinds of adsorbents and returns to the body, which reduces the loss of beneficial substances in plasma. Besides, there is another double filtration plasmapheresis, which uses two plasma filters with different apertures to separate plasma orderly; in this way the macromolecular substances, such as the immune globulin, can be selectively isolated in vitro, so as to save dosages of plasma and albumin solution. In the early 1980s, plasma exchange was mainly used in emergency treatment of toxic diseases. In China, Lanjuan Li’s team of Zhejiang University started to concentrate on the research of the artificial liver system in 1986. Based on researches on pathophysiology

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and the characteristics of liver failure, the plasma exchange, plasma perfusion, hemofiltration, and hemodialysis were systematically applied in the treatment of patients with liver failure for the first time, called Li-NBAL 1.0. It was innovatively proposed that, in clinical practice, different artificial liver methods can be used alone or in combination according to patient’s specific condition. For example, when liver failure is complicated with the hepatorenal syndrome, plasma exchange combined with hemodialysis or hemofiltration can be chosen. When liver failure is complicated with hepatic encephalopathy, plasma exchange combined with plasma perfusion can be used. For hyperbilirubinemia-dominated patients, plasma bilirubin adsorption or plasma exchange can be applied to reduce the level of the serum bilirubin so as to relieve pruritus. The artificial liver method with plasma exchange can not only efficiently eliminate a large number of toxic substances accumulated in the body (including endotoxin, bilirubin, bile acid, aromatic amino acid, ammonia, virus, etc.), but it can also supplement necessary substances such as the coagulation factor, lipoprotein, etc., so as to improve the prognosis of liver failure. The response rates of hepatitis gravis during the early stage, the middle stage, and the late stage were 90.9%, 71.0%, and 20.5%, respectively [7]. The artificial liver system can also help patients gain time for liver transplantation and improve the symptoms and the internal environment, which plays an important role in improving the success rate of transplant. In 1998, the research on the artificial liver system by Lanjuan Li’s team won the second prize in the national science and technology progress award. In view of the good effects that artificial liver system showed in the treatment of liver failure, in the late 1990s, Lanjuan Li’s team generously promoted the artificial liver system in China via different forms, including the establishment of training center, holding national and international artificial liver conferences, etc. From then on, the artificial liver system was gradually developed in other areas of China. With the increasingly mature technologies of hepatocyte isolation and culture, the cultured hepatocytes were introduced into the artificial liver system and a new generation of BAL emerged. Its basic structure is that the isolated hepatocytes are cultured in an external bioreactor, and then the patient’s blood or plasma flows pass through the reactor, where there is an exchange of substance with the cultured hepatocytes through a semipermeable membrane or by direct contact. Hepatocytes play a role in the functions of detoxification, synthesis, and biotransformation, so as to achieve the supporting effect. In that period, in order to achieve better therapeutic effects, scholars explored a lot of researches regarding the subjects of long-term culture of the hepatocytes, the maintenance of the function, the design of the bioreactor, the cryopreservation, resuscitation of the hepatocytes, etc.

1.2.4  T  he Twenty-First Century: New Devices Are Constantly Introduced According to the pathophysiological characteristics of liver failure, Lanjuan Li’s team developed a new design of NBAL, which combined plasma exchange, plasma adsorption, and hemofiltration, namely Li-NBAL 2.0 (The schematic diagram is

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shown in Fig. 1.1) [8]. The Li-NBAL 2.0 consists of four functional units, including plasma isolation, plasma exchange, plasma adsorption, and filtration. The independently developed dual-cavity plasma storage bag is introduced into the circulation to improve the efficiency of the toxic substances removal. Li-NBAL 2.0 carries out small doses of plasma exchange first, then followed by plasma adsorption (anion resin and activated carbon adsorption), hemofiltration to remove various harmful substances in plasma and to implement the functions of detoxification, synthesis, immune regulation, and maintaining the balance of water and electrolytes. In 2014, the animal study of Li-NBAL 2.0 was completed. Clinical trial of Li NBAL2.0 is ongoing. At present, the main NBAL devices in Europe are the MARS™ system and the Prometheus™ system. The MARS™ system is a combined application of albumin dialysis, adsorption, and conventional hemodialysis. The Prometheus™ system consists of fractionated plasma separation and adsorption (FPSA) combined with high flux hemodialysis [9, 10]. In 1999, the MARS™ system was formally applied in clinical treatment; it consists of three cycles, namely, blood cycle, albumin regeneration cycle, and dialysis cycle. When blood flows through the MARS™ FLUX dialyzer, the albumin-bound toxins and water-soluble toxins are transferred into the albumin circulating dialysate. In the albumin circuit, the activated carbon and resin absorption column was united to absorb albumin-bound toxins and small/medium molecular toxins. Finally, it corrects water, electrolyte acid-base disorders in the patient through a dialysis cycle (Fig. 1.2). The security of MARS™ system in clinical application is good; this system is able to improve the hyperdynamic circulation and low pressure of patients. Substances that can be removed by the system include bilirubin, bile acids, aromatic amino acids, inflammatory factors, nitric oxide, etc. [11, 12]. Regarding the structure, there are the following differences between Li-NBAL 2.0 and MARS™: (1) Li-NBAL 2.0 contains plasma exchange, which can rapidly remove various toxins. It can also balance the level of cytokines, regulate immune weigh Hemofiltration substituted liquid

Separating pump Part

Pacc P2nd

P1st

Returning pump

Fig. 1.1  Schematic diagram of Li-NBAL 2.0

Dual-chamber reservoir bag

Roller pump

High-fluxherrofilter

Pven

Anionexchange resin

Charcoal

Patient

Plasmoflo OP-02w

Heparin

P3rd

Replacement fluid pump

Blood pump

Filtration pump

Discard liquid weigh

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system, and supplement the coagulation factors and proteins to achieve the substitution of the liver synthetic function. However, MARS™ lacks the ability of substitution for liver synthesis. (2) The plasma adsorption cycle of Li-NBAL 2.0 is similar to the albumin cycle of MARS™. They both adopt activated carbon adsorption combined with the anion resin adsorption. However, in the plasma adsorption cycle, Li-NBAL 2.0 uses patient’s self-plasma, while the MARS™ uses high concentration albumin (20%) 500–600 ml, which has a high cost. (3) High flux hemofiltration is used by Li-NBAL 2.0, which can eliminate toxins and cytokines in the middle and low molecular weight. This is more suitable for patients with liver failure. Regarding MARS™, a low flux dialyzer is used, and the toxin removal range is smaller than Li-NBAL 2.0, which mainly eliminates toxins with small molecular weight. In a randomized controlled study, Lanjuan Li’s team used a porcine liver failure model to evaluate the efficacy of Li-NBAL 2.0 and MARS™ in the treatment of acute liver failure [8]. Twenty-four experimental mini-pigs weighting 23–30  kg were selected to build the model of acute liver failure. After the establishment of the model, the experimental animals were randomly divided into three groups, including acute liver failure control group (n = 8), MARS™ treatment group (n = 8), and Li-NBAL 2.0 treatment group (n = 8). The intervention treatment, which lasted 6 h, started 36 h after the establishment of the model. The experimental research showed that the survival time of Li-NBAL 2.0 group was significantly longer than those of MARS™ group and those of control group. The survival time of the animals in the acute liver failure control group was 61.6  ±  2.1  h, while the survival time for MARS™ treatment group and Li-NBAL 2.0 group was 73.5 ± 2.2 h and 89.1 ± 3.8 h, respectively. As shown in the following figure, MARS™ and Li-NBAL 2.0 treatments can significantly prolong the survival time of the animals with acute liver failure (p