Bioartificial Liver Treatment Research Articles

Fiber scaffold bioartificial liver therapy relieves acute liver failure and extrahepatic organ injury in pigs.

Rationale: Acute liver failure (ALF) causes severe liver injury and a systemic inflammatory response, leading to multiorgan failure with a high short-term mortality. Bioartificial liver (BAL) therapy is a promising approach that is hampered by the lack of appropriate bioreactors and carriers to retain hepatic cell function and poor understanding of BAL treatment mechanisms in ALF and extrahepatic organ injury. Recently, we used a fiber scaffold bioreactor (FSB) for the high-density, three-dimensional (3D) culture of primary porcine hepatocytes (PPHs) combined with an absorption component to construct a BAL and verified its function in a D-galactosamine (D-gal)-induced ALF porcine model to evaluate its protective effects on the liver and extrahepatic organs.Methods: Male pigs were randomized into standard/supportive therapy (ST), ST+no-cell BAL (ST+Sham BAL) and ST+BAL groups and received treatment 48 h after receiving a D-gal injection. Changes in blood chemistry and clinical symptoms were monitored for 120 h. Tissues and plasma were collected for analysis by pathological examination, immunoblotting, quantitative PCR and immunoassays.Results: PPHs cultured in the FSB obtained sufficient aeration and nutrition for high-density, 3D culture and maintained superior viability and functionality (biosynthesis and detoxification) compared with those cultured in flasks. All the animals developed ALF, acute kidney injury (AKI) and hepatic encephalopathy (HE) 48 h after D-gal infusion and received corresponding therapies. Animals in the BAL group showed markedly improved survival (4/5; 80%) compared with those in the ST+Sham BAL (0/5; p < 0.001) and ST (0/5; p < 0.001) groups. The levels of blood ammonia and biochemical and inflammatory indices were alleviated after BAL treatment. Increased liver regeneration and attenuations in the occurrence and severity of ALF, AKI and HE were observed in the ST+BAL group compared with the ST (p = 0.0009; p = 0.038) and ST+Sham BAL (p = 0.011; p = 0.031) groups. Gut leakage, the plasma endotoxin level, bacterial translocation, and peripheral and neuroinflammation were alleviated in the ST+BAL group compared with those in the other groups.Conclusions: BAL treatment enhanced liver regeneration and alleviated the systemic inflammatory response and extrahepatic organ injury to prolong survival in the ALF model and has potential as a therapeutic approach for ALF patients.

RL-1 Novel Human-derived Bio-artificial Liver Treatment in Patients of HBV Related ACLF

RL-1 Novel Human-derived Bio-artificial Liver Treatment in Patients of HBV Related ACLF

Randomized Trial of Spheroid Reservoir Bioartificial Liver in Porcine Model of Posthepatectomy Liver Failure.

Acute liver failure (ALF) is a catastrophic condition that can occur after major liver resection. The aim of this study was to determine theeffects ofthe spheroid reservoir bio-artificial liver (SRBAL) on survival, serum chemistry, and liver regeneration in posthepatectomy ALF pigs. Wild-type large white swine (20 kg-30 kg) underwentintracranial pressure (ICP) probe placementfollowed by 85% hepatectomy. Computed tomography (CT) volumetrics were performed to measure the extent of resection, and at 48 hours following hepatectomy to assess regeneration of the remnant liver. Animals were randomized into three groups based on treatment delivered 24-48 hours after hepatectomy: Group1-standard medical therapy (SMT, n = 6); Group2-SMT plus bio-artificial liver treatment using no hepatocytes (0 g, n = 6); and Group3-SMT plus SRBAL treatment using 200 g of primary porcine hepatocyte spheroids (200 g, n = 6). The primary endpoint was survival to 90 hours following hepatectomy. Death equivalent was defined as unresponsive grade 4 hepatic encephalopathy or ICP greater than 20 mmHg with clinical evidence of brain herniation. All animals in both (SMT and 0 g) control groups met the death equivalent before 51 hours following hepatectomy. Five of 6 animals in the 200-g group survived to 90 hours (P < 0.01). The mean ammonia, ICP, and international normalized ratio values were significantly lower in the 200-g group. CT volumetrics demonstrated increased volume regeneration at 48 hours following hepatectomy in the 200-g group compared with the SMT (P < 0.01) and 0-g (P < 0.01) groups. Ki-67 staining showed increased positive staining at 48 hours following hepatectomy (P < 0.01). Conclusion: The SRBAL improved survival, reduced ammonia, and accelerated liver regeneration in posthepatectomy ALF. Improved survival was associated with a neuroprotective benefit of SRBAL therapy. These favorable results warrant further clinical testing of the SRBAL.

Co‐culture with mesenchymal stem cells enhances metabolic functions of liver cells in bioartificial liver system

Bioartificial liver provides a combination of three-dimensional support, matrix interactions, and extracellular cues to create a bio-mimic microenvironment for maintaining hepatic-specific functions of liver cells in vitro. However, its transformal and metabolic functions are not yet satisfactory for clinic application. In this study, hepatoma-derived C3A cells were co-cultured with human placental mesenchymal stem cells (hPMSC) in microspheres placed in a fluidized bioreactor. The secretion of albumin and urea, the expression of metabolizing enzymes at both transcriptional and translational levels and the drug metabolism functions of co-cultured C3A cells were determined. With the three-dimensional culture system, when C3A cells were co-cultured with hPMSCs in separate microspheres, the secretion of albumin and activity of CYP1A2 were significantly improved although the enhancement of urea synthesis and CYP3A4 activity was less prominent. Combining co-culture system with fluidization significantly increased the secretion of urea and the activities of CYP1A2, CYP3A4 but not the albumin synthesis. Interestingly, the levels of phospho-PKA (Thr 197), phospho-PKC, phospho-ERK1/2 (Thr 202/Tyr 204) and CaMKII were all found to decrease in co-cultured C3A cells, implicating suppressed signaling pathways in those cells. Taken together, our results suggest that co-culturing of liver cells with hPMSC cells in three-dimensional fluidized bioreactor significantly improved the preservation of liver cells' metabolic functions which may greatly enhance the efficacy of bioartificial liver treatment.

Immunosafety Evaluation of a Multilayer Flat-Plate Bioartificial Liver

IntroductionTo study and evaluate the immunosafety of our newly developed multilayer flat-plate bioartificial liver (BAL) in treatment of canines with acute liver failure. MethodsFresh porcine hepatocytes and bone marrow mesenchymal stem cells were cocultured in new BAL. Ten canine models with acute liver failure were set up through D-galactosamine administration; 24 hours after administration, the beagles were randomly allocated to a 6-hour treatment with the BAL. The beagles were divided into 2 groups by treatment times. Group 1 beagles (n = 5) received a single BAL treatment. Group 2 beagles (n = 5) received 3 BAL treatments. The hemodynamic, hematologic response and humoral immune responses to BAL therapy were studied before and after treatments. ResultsAll beagles remained hemodynamically and hematologically stable during BAL treatments. The levels of IgG and IgM were similar before and after treatment after a single treatment. In addition, the level of CH50 in group 1 slightly decreased after the initiation of BAL treatment, and then the level recovered to baseline quickly after treatments. Time-course changes of the levels of antibodies and CH50 after 3 treatments in group 2 were similar to group 1. Only trace levels of IgG were detected in BAL medium after treatments. ConclusionThe multilayer flat-plate BAL showed a great immunosafety in the treatment of canines with acute liver failure and exhibited a good prospect of its use in clinic.

Artificial Liver Support System Reduces Intracranial Pressure More Effectively than Bioartificial System: An Experimental Study

Extracorporeal liver support (ELS) may play a role in bridging therapy in patients with acute liver failure (ALF). The aim of this study was to compare the influence of nonbiological and biological methods on intracranial pressure (ICP) in an animal model of ALF. A surgical devascularization model of ALF in pigs (35-40 kg) was used. Elimination therapy started after the onset of hypoglycemia. Biochemical parameters (bilirubin, ammonia, lactate, etc.) as well as ICP and cerebral perfusion pressure (CPP) were monitored for 12 hours. Of the total 31 pigs with ALF, 14 animals were treated by fractionated plasma separation and absorption (FPSA), 10 were treated with a bioartificial liver (BAL), and 7 animals were used as a control group. FPSA and BAL treatment started on average 3 hours 17 minutes and 2 hours 21 minutes, after devascularization and lasted for 5 hours 54 minutes and 5 hours 43 minutes, respectively. Ammonia levels were lower in the FPSA group, and bilirubin levels differed significantly in both the FPSA and BAL groups compared with controls. However, ICP values were reduced more effectively in pigs treated by FPSA: 19.1 vs. 27.0 mm Hg at 9 hours, 22.5 vs. 28.7 mm Hg at 11 hours, and 24.0 vs. 33.0 mm Hg at 12 hours (p<0.05). The artificial liver support system FPSA reduced ICP values more effectively than the Performer O. Liver RanD BAL system. Compared with this BAL system, the nonbiological elimination method of FPSA is a simpler application with the advantage that it can be applied in a more continuous way.

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

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. To overview and evaluate the current clinical application and outcomes of extracorporeal BAL support system during the past 15years. 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. 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. Although BAL system proved to be a success in some clinical cases reported, it still needs to be improved greatly.

Membrane molecular weight cut off impacts immunological safety of a novel bioartificial liver system

Objective To investigate the influence of membrane molecular weight cut off in our bioartificial liver(BAL)system.Methods Beagle dogs were used for a model of acute liver failure through D-galactosamine administration.The acute liver failure Beagles were divided into two groups by the membrane molecular weight cut off.Group A was treated with BAL containing 200 kDa retention rating membrane.Group B was treated with BAL containing 1200 kDa retention rating membrane.Each group underwent two six-hour BAL treatments that were performed on day 1 and day 21.BAL medium were examined and levels of IgG,IgM,and complement hemolytic unit of 50％(CH50)antibodies were measured in all Beagles and.Results BAL treatment was associated with a significant decline in levels of CH50.1200 kDa group experienced a significant increase in levels of IgG and IgM after two BAL treatments.Significant levels of canine proteins were detected in BAL medium from 1200 kDa group.Conclusions Xenogeneic immune response in the BAL system was influenced by membrane molecular weight cut off. Key words: Bioartificial liver; Membrane molecular weight cut off; Porcine hepatocyte; Bone marrow mesenchymal stem cells

Evaluation of a reversibly immortalized human hepatocyte line in bioartificial liver in pigs

An appropriate cell source is essential for the clinical application of bioartificial liver (BAL) system. This study aimed to test a reversibly immortalized human hepatocyte line (HepLi-4) in our newly validated choanoid fluidized bed bioreactor based BAL in pigs with fulminant hepatic failure (FHF). 15 FHF pigs were allocated to three groups: a BAL group receiving BAL treatment with HepLi-4 cells; a sham BAL group receiving cell-free BAL treatment; and a FHF group receiving intensive care only. Expression of liver-specific genes in HepLi-4 cells before and after BAL was analyzed, adult human hepatocytes acted as a reference. In BAL group, Fischer index was higher and serum indirect bilirubin level was lower compared with two control groups. Survival time in BAL group was longer than that in two control groups, but the difference was not statistically significant. Gene expression analysis showed that the transcript levels of liver-specific genes in HepLi-4 were retained after BAL, but significant variations were observed between HepLi-4 and human hepatocytes. HepLi-4 showed beneficial metabolic effects on FHF pigs in BAL, but is still not an appropriate cell source for BAL. More insights into interpreting the conditions for hepatocyte differentiation are needed. Key words : Reversible immortalization, hepatocytes, bioartificial liver, fulminant hepatic failure.

An experimental study on the effects of membrane molecular weight cut off on a novel bioartificial liver system

Objective To study the effects of membrane molecular weight cut off on a novel bioartificial liver(BAL) system.Methods Healthy beagles underwent 6-hour treatment with a BAL containing membrane with 200 kDa retention rating or 1200 kDa retention rating.The functional changes and cell viability were characterized.Results Hepatocyte performance levels such as albumin secretion,urea synthesis and viability were significantly higher in the 200 kDa retention rating group when compared with the 1200 kDa retention rating group (P＜0.05).Significant levels of canine proteins were detected in the BAL medium from the 1200 kDa retention rating group.Fluorescence microscopy further verified that heavy deposition of canine IgG,IgM and complement (C3) on co-culture cells were obtained after BAL treatment in the 1200 kDa retention rating group.Conclusions Small membrane molecular weight cut off of BAL could reduce the transfer of xenoreactive antibodies into the BAL medium and improved the performance of the BAL. Key words: Bioartificial liver; Membrane molecular weight cut off; Hepatocytes

New evidence of porcine endogenous retrovirus transmission with new bio-artificial liver system: a experimental study

To investigate the potential transmissibility of porcine endogenous retrovirus (PERV) from a newly-developed porcine hepatocyte bioartificial liver (BAL) system prior to human clinical trial by using a live canine model. Five normal beagles were treated with the new BAL support system for six hours. Samples of plasma from the BAL system and whole blood from the beagles were collected at regular intervals over the six month study period. DNA and RNA were isolated from both the peripheral blood mononuclear cells (PBMCs) and plasma for evaluation by polymerase chain reaction (PCR) and reverse transcription (RT)-PCR, respectively, to detect PERV and the Sus scrofa cytochrome B normalization standard. In addition, RT activity and the in vitro infectivity of the plasma were detected in HEK293 cells. All five beagles remained in stable physical health throughout the treatment and survived until the end of the study. PERV RNA-positivity and RT activity were only detected in the plasma samples from the 3rd BAL treatment cycle. All other samples, including PBMCs and plasma, were negative for PERV RNA, PERV DNA, and RT activity. In addition, none of the sera samples showed in vitro infectivity. Application of our BAL system does not lead to PERV transmission.

The Influence of Membrane Molecular Weight Cutoff on a Novel Bioartificial Liver

Given the xenogeneic immune reaction relevant to the molecular weight cutoff of the membrane of a bioartificial liver (BAL) system, we investigated the influence of membrane molecular weight cutoff in our BAL system in this study. Acute liver failure in beagles was induced by d-galactosamine administration. Eight beagles were divided into two groups by the membrane molecular weight cutoff of the plasma component separator. Group 1 beagles were treated with BAL containing 200 kDa retention rating membrane. Group 2 beagles were treated with BAL containing 1200 kDa retention rating membrane. Each group underwent two 6-h BAL treatments that were performed on day 1 and day 21. The hemodynamic and hematologic response, humoral immune responses, and cytotoxic immune response to BAL therapy were studied before and after treatments. All beagles remained hemodynamically and hematologically stable during BAL treatments. BAL treatment was associated with a significant decline in levels of complement; however, a longer time of level maintenance was observed in Group 2. Group 2 beagles experienced a significant increase in levels of IgG and IgM after two BAL treatments. Significant levels of canine proteins were detected in BAL medium from Group 2; only trace levels of canine proteins were detected in BAL medium from Group 1. The posttreatment viability of co-culture cells in Group 2 was lower compared with Group 1, and the viability of co-culture cells after treatments was associated with deposition of canine proteins on the cells. Xenogeneic immune response was influenced by membrane molecular weight cutoff in the BAL.

Effects of Membrane Molecular Weight Cutoff on Performance of a Novel Bioartificial Liver

Immunoisolation using semipermeable membranes has been incorporated into bioartificial liver (BAL) devices to separate cellular components of the recipient's immune system from the cells within the BAL device. This study was designed to explore the influence of membrane molecular weight cutoff on performance of the multilayer radial-flow BAL using porcine hepatocytes cocultured with mesenchymal stem cells. In this study, healthy beagles underwent 6-h treatment with a BAL containing membrane with 200 kDa retention rating or 1200 kDa retention rating. Functional markers of BAL performance were monitored before and after treatment, as well as cytotoxic immune response to BAL therapy. The results showed that hepatocyte performance levels such as albumin secretion, urea synthesis, and viability were all significantly higher in 200 kDa retention rating group compared with the 1200 kDa retention rating group after treatment (P < 0.05). Significant levels of canine proteins were detected in BAL medium from the 1200 kDa retention rating group. Fluorescence microscopy further verified that heavy deposition of canine IgG, IgM, and complement (C3) on coculture cells was obtained after BAL treatment in the 1200 kDa retention rating group. However, only trace deposits of canine immunoproteins were observed on coculture cells obtained from BAL in the 200 kDa retention rating group. Small membrane molecular weight cutoff of the BAL could reduce the transfer of xenoreactive antibodies into the BAL medium and improve the performance of the BAL.

Long-term absence of porcine endogenous retrovirus infection in chronically immunosuppressed patients after treatment with the porcine cell-based Academic Medical Center bioartificial liver

Clinical use of porcine cell-based bioartificial liver (BAL) support in acute liver failure as bridging therapy for liver transplantation exposes the patient to the risk of transmission of porcine endogenous retroviruses (PERVs) to human. This risk may be enhanced when patients receive liver transplant and are subsequently immunosuppressed. As further follow-up of previously reported patients (Di Nicuolo et al. 2005), an assessment of PERV infection was made in the same patient population pharmacologically immunosuppressed for several years after BAL treatment and in healthcare workers (HCWs) involved in the clinical trial at that time. Plasma and peripheral blood mononuclear cells (PBMCs) from eight patients treated with the Academic Medical Center-BAL (AMC-BAL), who survived to transplant, and 13 HCWs, who were involved in the trial, were assessed to detect PERV infection. A novel quantitative real-time polymerase chain reaction assay has been used. Eight patients who received a liver transplant after AMC-BAL treatment are still alive under long-term pharmacological immunosuppression. The current clinical follow-up ranges from 5.6 to 8.7 yr after BAL treatment. A new q-real-time PCR assay has been developed and validated to detect PERV infection. The limit of quantification of PERV DNA was ≥ 5 copies per 1 × 10(5) PBMCs. The linear dynamic range was from 5 × 10(0) to 5 × 10(6) copies. In both patients and HCWs, neither PERV DNA in PBMCs nor PERV RNA in plasma and PBMC samples have been found. Up to 8.7 yr after exposure to treatment with porcine liver cell-based BAL, no PERV infection has been found in long-term immunosuppressed patients and in HCWs by a new highly sensitive and specific q-real-time PCR assay.

Survival of liver failure pigs by transplantation of reversibly immortalized human hepatocytes with Tamoxifen-mediated self-recombination

Hepatocyte transplantation and bioartificial liver treatment are attractive alternatives to liver transplantation. The availability of well-characterized human hepatocyte lines facilitates such cell therapies. Human hepatocytes were immortalized with a retroviral vector SSR#197 expressing catalytic subunit of human telomerase reverse transcriptase (hTERT) and enhanced green fluorescent protein (EGFP) cDNAs flanked by a pair of loxP recombination targets. Then, Tamoxifen-dependent Cre recombinase was expressed in SSR#197-immortalized hepatocytes. Cre/LoxP recombination was performed in the established cells by simple exposure to 500 nM Tamoxifen for a week. Then, the reverted population of the cells was recovered by EGFP-negative cell sorting and characterized in vitro and in vivo using a pig model of acute liver failure (ALF) induced by d-galactosamine (0.5 g/kg) injection. A human hepatocyte cell line 16T-3 was established. Reverted 16-T3 cells showed the increased expression of hepatic markers in association with enhanced levels of transcriptional factors. Compared to normal human hepatocytes, albumin production and lidocaine-metabolizing activities of reverted 16-T3 cells were 0.32 and 0.50-fold, respectively. Transplantation of reverted 16T-3 cells significantly prolonged the survival of ALF pigs. Here we demonstrate the usefulness of Cre/LoxP -mediated reversible immortalization of human hepatocytes with Tamoxifen-mediated self-recombination.

The Significant Improvement of Survival Times and Pathological Parameters by Bioartificial Liver with Recombinant HepG2 in Porcine Liver Failure Model

We developed a bioartificial liver (BAL) containing human hepatoblastoma cell line, HepG2, with the addition of ammonia removal activity by transfecting a glutamine synthetase (GS) gene and estimated the efficacy using pigs with ischemic liver failure. GS-HepG2 cells showed 15% ammonia removal activity of porcine hepatocytes, while unmodified HepG2 had no such activity. The established GS-HepG2 cells were grown in a circulatory flow bioreactor to 3.5-4.1 x 10(9) cells. Survival time of the animals treated with GS-HepG2 BAL was significantly prolonged compared to the cell-free control (14.52 +/- 5.24 h vs. 8.53 +/- 2.52 h) and the group treated with the BAL consisting of unmodified wild-type HepG2 (9.58 +/- 4.52 h). Comparison showed the cell-containing BAL groups to have significantly fewer incidences of increased brain pressure. Thus, the GS-HepG2 BAL treatment resulted in a significant improvement of survival time and pathological parameters in pigs with ischemic liver failure.

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

To evaluate the functions of a new bioartificial liver (BAL) system in vitro and in vitro. 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. 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. The new BAL system has the ability to perform liver functions and can be used to treat ALF.

Comparison between bioartificial and artificial liver for the treatment of acute liver failure in pigs

To characterize and evaluate the therapeutic efficacy of bioartificial liver (BAL) as compared to that of continuous hemodiafiltration (CHDF) with plasma exchange (PE), which is the current standard therapy for fulminant hepatic failure (FHF) in Japan. Pigs with hepatic devascularization were divided into three groups: (1) a non-treatment group (NT; n = 4); (2) a BAL treatment group (BAL; n = 4), (3) a PE + CHDF treatment group using 1.5 L of normal porcine plasma with CHDF (PE + CHDF, n = 4). Our BAL system consisted of a hollow fiber module with 0.2 mum pores and 1 multiply 10(10) of microcarrier-attached hepatocytes inoculated into the extra-fiber space. Each treatment was initiated 4 h after hepatic devascularization. The pigs in the BAL and the PE + CHDF groups survived longer than those in the NT group. The elimination capacity of blood ammonia by both BAL and PE + CHDF was significantly higher than that in NT. Aromatic amino acids (AAA) were selectively eliminated by BAL, whereas both AAA and branched chain amino acids, which are beneficial for life, were eliminated by PE + CHDF. Electrolytes maintenance and acid-base balance were better in the CPE + CHDF group than that in the BAL group. Our results suggest that PE + CHDF eliminate all factors regardless of benefits, whereas BAL selectively metabolizes toxic factors such as AAA. However since PE + CHDF maintain electrolytes and acid-base balance, a combination therapy of BAL plus CPE + CHDF might be more effective for FHF.

Evaluation of a bioartificial liver based on a nonwoven fabric bioreactor with porcine hepatocytes in pigs

We developed a bioartificial liver (BAL) based on a direct hemoperfusion typed nonwoven fabric bioreactor containing porcine hepatocytes. In this study, the efficacy of our BAL was evaluated with a pig fulminant hepatic failure (FHF) model. FHF was induced with intravenous administration of D-galactosamine (1.3 g/kg) in each pig. Twelve hours post D-galactosamine injection, fifteen pigs were divided into: a BAL group (n = 5), in which pigs received the BAL treatment with 1.0 to 1.3 x 10(9) hepatocytes for 6 h, a sham BAL group (n = 5), in which pigs received the BAL treatment without hepatocytes, and a FHF group (n = 5), in which pigs only received intensive care. Parameters related to liver function and animal survival up to 168 h were determined. In the BAL group, blood ammonia and plasma lactate levels were lower, and serum glucose levels and Fischer index were higher than those in the other two groups. Survival time of pigs in the BAL group was significantly prolonged as compared with the sham BAL and the FHF group. The BAL based on a nonwoven fabric bioreactor containing porcine hepatocytes appears to be effective in the treatment of FHF in pigs.

CRYOPRESERVED HUMAN HEPATOCYTES FROM CELL BANK: IN VITRO FUNCTION AND CLINICAL APPLICATION

P658 Aims: the development of a National Bank of Human Hepatocytes, isolated from livers unwanted for transplantation at harvesting, allows to obtain live hepatic tissue usable for in vitro and clinical evaluation of cell therapy and transplantation and bioartificial organs. The aim of this study is to analyze in vitro function of isolated and cryopreserved human hepatocytes from cell Bank and define their potential clinical application in a bioartificial liver (BAL) device. Methods: 103 not transplantable livers were utilized for human hepatocytes isolation and cryopreservation from July 2001 to December 2003 in the Nord Italia Transplant area (NITp and AIRT). Hepatocytes were isolated by collagenase-enzymatic digestion. Isolated hepatic cells were analyzed in terms of yield, viability (tripan blue and XTT test), diazepam metabolism (cyt P450 activity) and production of human albumin (immunonephelometry and mRNA by RT-PCR) after isolation (fresh hepatocytes) and after cryopreservation (10% DMSO) in liquid nitrogen. Results: macrosteatosis >60%, ischemic damage due to prolonged donor hypotension or cardiac arrest and non-viral cirrhosis were the causes of refusal of the liver for transplantation respectively in 60%, 11% and 8% of cases. Cell yield averaged 7 million of hepatocytes per gram of liver tissue digested; mean viability was 80%±13%. The best results in terms of cell yield and viability were obtained from steatotic organs, while cirrhotic livers yielded less cell/gr of liver (3x106 vs 7x105 p<0.043 and 81% vs 66% p=0.27, respectively). Viability of cryopreserved hepatocytes after thawing averaged 50%. However thawed hepatocytes had a normal diazepam metabolism (fig 1) and human albumin synthesis was comparable to that of fresh cells (fig 2).FigureFigureCryopreserved human hepatocytes (CHH) were utilized as the biological component of a BAL device for temporaneous support of two patients affected by FHF awaiting for urgent transplant. A total of 3 BAL applications were performed. Ten to 13 billion viable CHH have been loaded in each BAL. No adverse events were recorded and vital functions remained table during the procedures. Biochemical liver functions showed bilirubin and ammonia reduction at the end of each treatment with CHH based BAL. One patient was successfully bridged to emergency OLTx performed after a single BAL; in the second case there was a spontaneous recovery of liver function after two BAL treatment and surgical arterialization of the portal vein. Both patients are still alive and well at home. Conclusions: the recovery of donor human livers unwanted for transplantation at harvesting, allowed isolation and cryopreservation of viable and functionally active human hepatocytes which have been banked and successfully used for clinical application of a BAL device.