Alginate microencapsulated human hepatocytes for the treatment of acute liver failure in children.

Background & Aims: Liver transplantation (LT) is the most effective treatment for patients with acute liver failure (ALF), but is limited by surgical risks and the need for life-long immunosuppression. Transplantation of microencapsulated human hepatocytes in alginate is an attractive option over whole liver replacement. The safety and efficacy of hepatocyte microbead transplantation have been shown in animal models.

Cryopreservation of Hepatocyte Microbeads for Clinical Transplantation.

Intraperitoneal transplantation of hepatocyte microbeads is an attractive option for the management of acute liver failure. Encapsulation of hepatocytes in alginate microbeads supports their function and prevents immune attack of the cells. Establishment of banked cryopreserved hepatocyte microbeads is important for emergency use.

Alginate microencapsulated hepatocytes optimised for transplantation in acute liver failure.

Background And Aim: Intraperitoneal transplantation of alginate-microencapsulated human hepatocytes is an attractive option for the management of acute liver failure (ALF) providing short-term support to allow native liver regeneration. The main aim of this study was to establish an optimised protocol for production of alginate-encapsulated human hepatocytes and evaluate their suitability for clinical use.

Methods: Human hepatocyte microbeads (HMBs) were prepared using sterile GMP grade materials.

Coculture with mesenchymal stem cells results in improved viability and function of human hepatocytes.

Hepatocyte transplantation is becoming an accepted therapy for acute liver failure, either as a bridge to liver regeneration or to organ transplantation. Hepatocytes provide liver function in place of the failing organ. The maintenance of sufficient viability and function of the transplanted hepatocytes is a concern.

Ex vivo magnetic resonance imaging of transplanted hepatocytes in a rat model of acute liver failure.

Hepatocyte transplantation is being evaluated as an alternative to liver transplantation. However, the fate of hepatocytes after transplantation is not well defined. The aims of the study were to improve hepatocyte labeling in vitro using superparamagnetic iron oxide nanoparticles (SPIOs) and to perform in vivo experiments on tracking labeled cells by magnetic resonance imaging (MRI).

Use of indocyanine green for functional assessment of human hepatocytes for transplantation.

Background/objective: Hepatocyte transplantation is a promising alternative to liver transplantation in children with liver metabolic disorders and acute liver failure. Currently, it is difficult to assess rapidly hepatocyte function before transplantation. The aim of this study was to investigate whether the uptake and release of indocyanine green (ICG) by hepatocytes could be used.

Cryopreservation of human hepatocytes for clinical use.

Cryopreservation of hepatocytes is important for use both in research and for clinical application in hepatocyte transplantation. Cryopreservation causes damage to hepatocytes with the result that cell viability and function is reduced on thawing compared to fresh cells. There are many different protocols reported for freezing human hepatocytes mainly using DMSO as cryoprotectant.

N-acetylcysteine improves the viability of human hepatocytes isolated from severely steatotic donor liver tissue.

Hepatocyte transplantation is dependent on the availability of good quality human hepatocytes isolated from donor liver tissue. Hepatocytes obtained from livers rejected for transplantation on the grounds of steatosis are often of low viability and not suitable for clinical use. The aim of this study was to evaluate the effects of the antioxidant N-acetylcysteine (NAC) on the function of hepatocytes isolated from steatotic donor livers.

Optimization of the cryopreservation and thawing protocol for human hepatocytes for use in cell transplantation.

Cryopreservation of human hepatocytes is important for their use in hepatocyte transplantation. On thawing, cryopreserved hepatocytes often have reduced viability and metabolic function in comparison with fresh cells. The aim of this study was to modify the different steps in the standard cryopreservation procedure in an attempt to improve the overall outcome.

Experience of microbiological screening of human hepatocytes for clinical transplantation.

Hepatocyte transplantation is being used in patients with liver-based metabolic disorders and acute liver failure. Hepatocytes are isolated from unused donor liver tissue under GMP conditions. Cells must be free of microbiological contamination to be safe for human use.

Microbiological monitoring of hepatocyte isolation in the GMP laboratory.

For clinical hepatocyte transplantation, cells need to be prepared in a sterile GMP environment. Strict regulations are in place that set the standard for this environment that cells are prepared in. These regulations control all aspects of the environment.

Liver after hepatocyte transplantation for liver-based metabolic disorders in children.

There are limited data regarding donor hepatocyte engraftment into recipient liver after human hepatocyte transplantation (HHTx). We reviewed the explant livers of seven children with metabolic disorders [ornithine-transcarbamylase deficiency (one), coagulation factor VII deficiency (three), Crigler-Najjar syndrome (one), progressive familial intrahepatic cholestasis type 2 (PFIC-2) deficiency (two)] who received allograft hepatocytes by intraportal infusion with improvement in phenotype, although all later underwent liver transplantation (LT). Immunohistochemistry for bile salt export protein (BSEP) in the PFIC-2 patients and genetic typing following laser capture microdissection (LCM) of liver cells in the others were used to identify donor hepatocytes in recipient explant livers.

Cryopreservation-induced nonattachment of human hepatocytes: role of adhesion molecules.

Good quality cryopreserved human hepatocytes are becoming an important source for clinical hepatocyte transplantation. However, the process of cryopreservation leads to both structural and functional impairment of hepatocytes. The aim of this study was to investigate the mechanisms of cryopreservation-induced nonattachment in human hepatocytes.

The effects of immunosuppressive agents on the function of human hepatocytes in vitro.

Calcineurin inhibitors (tacrolimus) and steroids continue to be an important component of hepatocyte transplantation protocols, despite reports of hepatotoxicity and inhibitory effects of steroids on cell proliferation. The aim of the study was to investigate whether isolated human hepatocytes were more vulnerable to the toxicity of these agents and also to investigate their effects on hepatocyte VEGF secretion, a vascular permeability factor suggested to be involved in the cell engraftment process. Human hepatocytes were isolated from donor livers/segments rejected or unused for orthotopic liver transplantation using a collagenase perfusion technique.

Analysis of the effects of cryopreservation on rat hepatocytes using SELDI-TOF mass spectrometry.

Successful cryopreservation of hepatocytes is essential to the future of hepatocyte transplantation as a treatment for liver disease, and also for the improved in vitro use of hepatocytes for research. However, hepatocyte function is adversely affected by even the best cryopreservation protocols. To investigate possible mechanisms for these changes, total cell lysates were prepared from fresh and cryopreserved rat hepatocytes and the proteome profiles compared using SELDI-TOF-MS ProteinChip technology.

Isolation of hepatocytes from livers from non-heart-beating donors for cell transplantation.

One of the limitations to hepatocyte transplantation is the restricted availability of donor liver tissue. The aim of this study was to evaluate livers from non-heart-beating donors (NHBDs) as a source of hepatocytes for cell transplantation. A total of 20 livers/segments obtained from NHBD were perfused under good manufacturing practices using a standard collagenase digestion method.

Preincubation of rat and human hepatocytes with cytoprotectants prior to cryopreservation can improve viability and function upon thawing.

Cryopreservation of human hepatocytes is important for the treatment of liver disease by hepatocyte transplantation and also for the use of hepatocytes as an in vitro model of the liver. One factor in the success of cryopreservation is the quality of cells before freezing. Preincubation of hepatocytes with cytoprotective compounds to allow recovery from the isolation process prior to cryopreservation, such as those that will boost cellular adenosine triphosphate (ATP) content or antioxidants, may improve the viability and function of cells upon thawing.

The effects of cryopreservation on human hepatocytes obtained from different sources of liver tissue.

Successful cryopreservation of human hepatocytes is important to establish hepatocyte banks for clinical use or in vitro research. The availability of donor tissue from unused liver segments/lobes and non-heart-beating donors (NHBD) has provided newer sources of hepatocytes. The quality of hepatocytes at the time of cryopreservation is important as cells isolated from liver tissue of borderline quality may not withstand the stresses associated with cryopreservation and subsequent thawing.

Preincubation of rat and human hepatocytes with cytoprotectants prior to cryopreservation can improve viability and function upon thawing.

Cryopreservation of human hepatocytes is important for the treatment of liver disease by hepatocyte transplantation and also for the use of hepatocytes as an in vitro model of the liver. One factor in the success of cryopreservation is the quality of cells before freezing. Preincubation of hepatocytes with cytoprotective compounds to allow recovery from the isolation process prior to cryopreservation, such as those that will boost cellular adenosine triphosphate (ATP) content or antioxidants, may improve the viability and function of cells upon thawing.