Treatment of Acute Liver Failure in Mice by Hepatocyte Xenotransplantation

Abstract

Liver diseases still have a high mortality even though liver transplantation has become a standard treatment. Currently, hepatocyte transplantation has been proposed as another promising strategy. One limitation is the availability of human livers as a source of hepatocytes. Because of an unlimited supply, the use of porcine hepatocytes might address this problem. Regardless of the source, once isolated hepatocytes lose specific functionality due to the loss of the natural microenvironment. For this reason, we tested the ability of a selfassembling peptide nanofiber (SAPNF) to provide a provisional three-dimensional (3D) support to interact with cells to control their function in vivo. Isolated porcine hepatocytes were embedded in SAPNF, or collagen type I and transplanted by direct injection into the splenic pulp of SCID mice suffering from acute liver failure (ALF) by 90% hepatectomy. SAPNF porcine hepatocyte transplantation produced engraftment that was far superior to that obtained using collagen and prolonged the survival of mice with ALF, in contrast with controls. An ultrastructural evaluation using transmission electron microscopy indicated extensive cellcell communication and preservation of hepatocyte architecture. The transplanted SAPNF hepatocytes showed higher expression of albumin and PAS and lower apoptotic events assessed by TUNEL staining. Hepatocytes culture in a truly 3D network allows in vivo maintaining of differentiated functions, and once transplanted between widely divergent species can function to correct acute liver failure in mice and prolong their survival.

Profiling the Impact of Medium Formulation on Morphology and Functionality of Primary Hepatocytes in vitro

“…However, such cells would be contra-indicated for other cell therapeutic applications such as HTx, given that even with isolated cells from marginal human donor livers, low quality of such transplanted cells may be a major cause of equivocal efficacy in human clinical trials48. Indeed, ultrastructural evaluation of a porcine-based HTx strategy to treat ALF mice, showed phenotypic correlation with maintained hepatic architecture and functionality49.…”

Repeated transplantation of hepatocytes prevents fulminant hepatitis in a rat model of Wilson's disease

“…Transplantation at earlier time points or shortened intervals between transplant procedures might further improve the repopulation efficiency in animals with advanced disease and might thus improve the overall therapy outcome. Despite the high rate of liver repopulation achieved here without preconditioning, other regimens can result in improved therapeutic outcomes after a single transplant, as recently demonstrated in many excellent studies by Gupta et al28‐30 The pretreatment of the liver or the modification of isolated hepatocytes may thus further enhance the proliferation of transplanted cells and improve their attachment to sinusoids 51‐53. However, pretreatment regimens must be safe.…”

“…Despite the high rate of liver repopulation achieved here without preconditioning, other regimens can result in improved therapeutic outcomes after a single transplant, as recently demonstrated in many excellent studies by Gupta et al [28][29][30] The pretreatment of the liver or the modification of isolated hepatocytes may thus further enhance the proliferation of transplanted cells and improve their attachment to sinusoids. [51][52][53] However, pretreatment regimens must be safe. Notably, the treatment of patients by repeated hepatocyte transplantation has not been followed by detrimental effects.…”

Biological, Chemical, and Electronic Applications of Nanofibers

“…In addition to numerous animal studies on the above systems, nanofibers have been applied to a diverse range of other medical treatments. Injectable self‐assembling peptide nanofibers were loaded with growth factors derived from a conditionally immortalized human hepatocyte cell line186 or hepatocytes187 for the treatment of liver failure. The self‐assembling peptide/hepatocyte construct corrected acute liver failure in mice and prolonged their survival 187.…”

“…Injectable self‐assembling peptide nanofibers were loaded with growth factors derived from a conditionally immortalized human hepatocyte cell line186 or hepatocytes187 for the treatment of liver failure. The self‐assembling peptide/hepatocyte construct corrected acute liver failure in mice and prolonged their survival 187. In a rat model for abdominal wall replacement, PEUU nanofibers fabricated by a wet electrospinning technique provided a good healing with a mimic mechanical behavior as well as a substantial cellular infiltration 188.…”