Hybrid artificial liver support system for treatment of severe liver failure

Evaluation of G3BP1 in the prognosis of acute and acute-on-chronic liver failure after the treatment of artificial liver support system

BACKGROUND

The increased expression of G3BP1 was positively correlated with the prognosis of liver failure.

AIM

To investigate the effect of G3BP1 on the prognosis of acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) after the treatment of artificial liver support system (ALSS).

METHODS

A total of 244 patients with ALF and ACLF were enrolled in this study. The levels of G3BP1 on admission and at discharge were detected. The validation set of 514 patients was collected to verify the predicted effect of G3BP1 and the viability of prognosis.

RESULTS

This study was shown that lactate dehydrogenase (LDH), alpha-fetoprotein (AFP) and prothrombin time were closely related to the prognosis of patients. After the ALSS treatment, the patient' amount of decreased G3BP1 index in difference of G3BP1 between the value of discharge and admission (difG3BP1) < 0 group had a nearly 10-fold increased risk of progression compared with the amount of increased G3BP1 index. The subgroup analysis showed that the difG3BP1 < 0 group had a higher risk of progression, regardless of model for end-stage liver disease high-risk or low-risk group. At the same time, compared with the inflammatory marks [tumor necrosis factor-α, interleukin (IL)-1β and IL-18], G3BP1 had higher discrimination and was more stable in the model analysis and validation set. When combined with AFP and LDH, concordance index was respectively 0.84 and 0.8 in training and validation cohorts.

CONCLUSION

This study indicated that G3BP1 could predict the prognosis of ALF or ACLF patients treated with ALSS. The combination of G3BP1, AFP and LDH could accurately evaluate the disease condition and predict the clinical endpoint of patients.

Hollow Fiber and Nanofiber Membranes in Bioartificial Liver and Neuronal Tissue Engineering

To date, the creation of biomimetic devices for the regeneration and repair of injured or diseased tissues and organs remains a crucial challenge in tissue engineering. Membrane technology offers advanced approaches to realize multifunctional tools with permissive environments well-controlled at molecular level for the development of functional tissues and organs. Membranes in fiber configuration with precisely controlled, tunable topography, and physical, biochemical, and mechanical cues, can direct and control the function of different kinds of cells toward the recovery from disorders and injuries. At the same time, fiber tools also provide the potential to model diseases in vitro for investigating specific biological phenomena as well as for drug testing. The purpose of this review is to present an overview of the literature concerning the development of hollow fibers and electrospun fiber membranes used in bioartificial organs, tissue engineered constructs, and in vitro bioreactors. With the aim to highlight the main biomedical applications of fiber-based systems, the first part reviews the fibers for bioartificial liver and liver tissue engineering with special attention to their multifunctional role in the long-term maintenance of specific liver functions and in driving hepatocyte differentiation. The second part reports the fiber-based systems used for neuronal tissue applications including advanced approaches for the creation of novel nerve conduits and in vitro models of brain tissue. Besides presenting recent advances and achievements, this work also delineates existing limitations and highlights emerging possibilities and future prospects in this field.

Bioengineering Organs for Blood Detoxification

For patients with severe kidney or liver failure the best solution is currently organ transplantation. However, not all patients are eligible for transplantation and due to limited organ availability, most patients are currently treated with therapies using artificial kidney and artificial liver devices. These therapies, despite their relative success in preserving the patients' life, have important limitations since they can only replace part of the natural kidney or liver functions. As blood detoxification (and other functions) in these highly perfused organs is achieved by specialized cells, it seems relevant to review the approaches leading to bioengineered organs fulfilling most of the native organ functions. There, the culture of cells of specific phenotypes on adapted scaffolds that can be perfused takes place. In this review paper, first the functions of kidney and liver organs are briefly described. Then artificial kidney/liver devices, bioartificial kidney devices, and bioartificial liver devices are focused on, as well as biohybrid constructs obtained by decellularization and recellularization of animal organs. For all organs, a thorough overview of the literature is given and the perspectives for their application in the clinic are discussed.

Artificial liver support system in treatment of liver failure after acute poisoning

BACKGROUND

Acute poisoning (AP) may cause failure of the liver and kidney, and even death. This study aimed to investigate the efficacy of artificial liver support system (ALSS) on the treatment of liver failure after acute poisoning.

METHODS

A total of 31 patients with liver failure caused by AP were admitted to emergency ICU, central ICU, and Department of Gastroenterology from 2005 to 2009 in Zhongshan Hospital Affiliated to Xiamen University, China. Among them, 13 patients served as a treatment group, and used ALSS in addition to detoxification treatment and protective treatment of liver function, and the other 18 patients served as a control group receiving detoxification treatment and protective treatment of liver function.

RESULTS

In the treatment group, 10 patients (76.9%) were cured or improved, 2 died, and 1 was discharged against advice. In the 18 patients in the control group, 7 (38.9%) were cured or improved, 3 died, and 8 were discharged against advice. There was a significant difference in the rates of improvement between the two groups (P<0.05).

CONCLUSION

ALSS is a safe and effective clinical method for the treatment of acute toxic liver failure.

Systematic review: extracorporeal bio-artificial liver-support system for liver failure

BACKGROUND

Orthotopic liver transplantation (OLT) is the only effective long-term treatment for liver failure by now. However, it is not yet a perfect choice due to donor-organ shortage and the need of a lifelong immunosuppressive therapy. Therefore, it is necessary to find a new approach to fighting the disease. Several published clinical trials have reported the therapeutic effect of bio-artificial liver (BAL) for liver failure.

OBJECTIVE

To overview and evaluate the current clinical application and outcomes of extracorporeal BAL support system during the past 15 years.

METHODS

Relevant studies were retrieved from PubMed and Cochrane Library databases. Independent assessments and the final consensus decision were performed by three independent reviewers. Acceptable study designs included randomized controlled trials, controlled clinical trials, and case reports. A total of 31 studies were tabulated and critically appraised in terms of characteristics, methods, and outcomes.

RESULTS

There was a trend of falling into the normal ranges with the clinical and biochemical parameters after the BAL treatment. The neurological status of most patients was improved or stabilized during BAL treatment as well. No significant effect on survival could be seen after the BAL treatment.

CONCLUSIONS

Although BAL system proved to be a success in some clinical cases reported, it still needs to be improved greatly.

The influence of medium composition and matrix on long-term cultivation of primary porcine and human hepatocytes

The differentiated hepatocyte phenotype remains difficult to maintain in culture. The duration over which phenotypically stable hepatocytes can be cultured ranges from a couple of days to a few weeks. Shortcomings in medium formulation may be a factor in this lack of success. We have investigated effects of medium formulation on primary porcine and human hepatocyte cultures. We tested seven culture medium compositions (DMEM, ExCell 400, HepatoZYME-SFM, L-15 Leibovitz, SF-3, Waymouth, and Williams' E) and the effects of serum, fibronectin and biomatrix in a sandwich culture configuration. Albumin, urea, cholesterol, GOT, GPT, LDH and triglyceride concentrations were measured over 14 days. For both human and porcine cultures, the best results were obtained with SF-3 medium. Cells cultivated with Williams' E medium and FCS had good morphology and synthetic function during the first days of culture. However, continued addition of serum, was associated with a subsequent loss of differentiated phenotype. Addition of fibronectin was associated with improved function in cultures maintained in SF-3 medium whilst biomatrix had no effect. In contrast, addition of fibronectin did not influence cultures maintained in Williams' E medium, but cultures with biomatrix were associated with improved function at longer time points.

Functional evaluation of a new bioartificial liver system in vitro and in vitro

AIM

To evaluate the functions of a new bioartificial liver (BAL) system in vitro and in vitro.

METHODS

The BAL system was configured by inoculating porcine hepatocyte spheroids into the cell circuit of a hollow fiber bioreactor. In the experiments of BAL in vitro, the levels of alanine aminotransferase (ALT), total bilirubin (TB), and albumin (ALB) in the circulating hepatocyte suspension and RPMI-1640 medium were determined during 6 h of circulation in the BAL device. In the experiments of BAL in vitro, acute liver failure (ALF) model in canine was induced by an end-side portocaval shunt combined with common bile duct ligation and transaction. Blood ALT, TB and ammonia levels of ALF in canines were determined before and after BAL treatment.

RESULTS

During 6 h of circulation in vitro, there was no significant change of ALT, whereas the TB and ALB levels gradually increased with time both in the hepatocyte suspension and in RPMI-1640 medium. In the BAL treatment group, blood ALT, TB and ammonia levels of ALF in canines decreased significantly.

CONCLUSION

The new BAL system has the ability to perform liver functions and can be used to treat ALF.

Present and Future Developments in Hepatic Tissue Engineering for Liver Support Systems : State of the art and future developments of hepatic cell culture techniques for the use in liver support systems

The liver is the most important organ for the biotransformation of xenobiotics, and the failure to treat acute or acute-on-chronic liver failure causes high mortality rates in affected patients. Due to the lack of donor livers and the limited possibility of the clinical management there has been growing interest in the development of extracorporeal liver support systems as a bridge to liver transplantation or to support recovery during hepatic failure. Earlier attempts to provide liver support comprised non-biological therapies based on the use of conventional detoxification procedures, such as filtration and dialysis. These techniques, however, failed to meet the expected efficacy in terms of the overall survival rate due to the inadequate support of several essential liver-specific functions. For this reason, several bioartificial liver support systems using isolated viable hepatocytes have been constructed to improve the outcome of treatment for patients with fulminant liver failure by delivering essential hepatic functions. However, controlled trials (phase I/II) with these systems have shown no significant survival benefits despite the systems' contribution to improvements in clinical and biochemical parameters. For the development of improved liver support systems, critical issues, such as the cell source and culture conditions for the long-term maintenance of liver-specific functions in vitro, are reviewed in this article. We also discuss aspects concerning the performance, biotolerance and logistics of the selected bioartificial liver support systems that have been or are currently being preclinically and clinically evaluated.

Functional evaluation of a new bioartificial liver system in vivo and in vivo

AIM: To evaluate the functions of a new bioartificial liver (BAL) system in vitro and in vitro.

MEHTODS: The BAL system was configurated by inoculating porcine hepatocyte spheroids into the cell circuit of a hollow fiber bioreactor. In the experiments of BAL in vitro, the levels of alanine aminotransferase (ALT), total bilirubin (TB), and albumin (ALB) in the circulating hepatocyte suspension and RPMI-1640 medium were determined during 6 h of circulation in the BAL device. In the experiments of BAL in vitro, acute liver failure (ALF) model in canine was induced by an end-side portocaval shunt combined with common bile duct ligation and transaction. Blood ALT, TB and ammonia levels of ALF in canines were determined before and after BAL treatment.

RESULTS: During 6 h of circulation in vitro, there was no significant change of ALT, whereas the TB and ALB levels gradually increased with time both in the hepatocyte suspension and in RPMI-1640 medium. In the BAL treatment group, blood ALT, TB and ammonia levels of ALF in canines decreased significantly.

CONCLUSION: The new BAL system has the ability to perform liver functions and can be used to treat ALF.