Will nano-fibers permit to turn liver cell transplantation into a curative tool against liver failure?

Pluripotent Stem Cell-derived Strategies to Treat Acute Liver Failure: Current Status and Future Directions

Liver disease has long been a heavy health and economic burden worldwide. Once the disease is out of control and progresses to end-stage or acute organ failure, orthotopic liver transplantation (OLT) is the only therapeutic alternative, and it requires appropriate donors and aggressive administration of immunosuppressive drugs. Therefore, hepatocyte transplantation (HT) and bioartificial livers (BALs) have been proposed as effective treatments for acute liver failure (ALF) in clinics. Although human primary hepatocytes (PHs) are an ideal cell source to support these methods, the large demand and superior viability of PH is needed, which restrains its wide usage. Thus, a finding alternative to meet the quantity and quality of hepatocytes is urgent. In this context, human pluripotent stem cells (PSC), which have unlimited proliferative and differential potential, derived hepatocytes are a promising renewable cell source. Recent studies of the differentiation of PSC into hepatocytes has provided evidence that supports their clinical application. In this review, we discuss the recent status and future directions of the potential use of PSC-derived hepatocytes in treating ALF. We also discuss opportunities and challenges of how to promote such strategies in the common applications in clinical treatments.

Cells and materials for liver tissue engineering

Liver transplantation is currently the most efficacious treatment for end-stage liver diseases. However, one main problem with liver transplantation is the limited number of donor organs that are available. Therefore, liver tissue engineering based on cell transplantation that combines materials to mimic the liver is under investigation with the goal of restoring normal liver functions. Tissue engineering aims to mimic the interactions among cells with a scaffold. Particular materials or a matrix serve as a scaffold and provide a three-dimensional environment for cell proliferation and interaction. Moreover, the scaffold plays a role in regulating cell maturation and function via these interactions. In cultures of hepatic lineage cells, regulation of cell proliferation and specific function using biocompatible synthetic, biodegradable bioderived matrices, protein-coated materials, surface-modified nanofibers, and decellularized biomatrix has been demonstrated. Furthermore, beneficial effects of addition of growth factor cocktails to a flow bioreactor or coculture system on cell viability and function have been observed. In addition, a system for growing stem cells, liver progenitor cells, and primary hepatocytes for transplantation into animal models was developed, which produces hepatic lineage cells that are functional and that show long-term proliferation following transplantation. The major limitation of cells proliferated with matrix-based transplantation systems is the high initial cell loss and dysfunction, which may be due to the absence of blood flow and the changes in nutrients. Thus, the development of vascular-like scaffold structures, the formation of functional bile ducts, and the maintenance of complex metabolic functions remain as major problems in hepatic tissue engineering and will need to be addressed to enable further advances toward clinical applications.

Transplantation of porcine hepatocytes cultured with polylactic Acid-o-carboxymethylated chitosan nanoparticles promotes liver regeneration in acute liver failure rats

In this study, free porcine hepatocytes suspension (Group A), porcine hepatocytes embedded in collagen gel (Group B), porcine hepatocytes cultured with PLA-O-CMC nanoparticles and embedded in collagen gel (Group C), and PLA-O-CMC nanoparticles alone (Group D) were transplanted into peritoneal cavity of ALF rats, respectively. The result showed that plasma HGF levels were elevated post-transplantation with a peak at 12 hr. The rats in Group C showed highest plasma HGF levels at 2, 6, 12, 24 and 36 hr post-transplantation and lowest HGF level at 48 hr. Plasma VEGF levels were elevated at 48 hr post-transplantation with a peak at 72 hr. The rats in Group C showed highest plasma HGF levels at 48, 72, and 96 hr post-transplantation. The liver functions in Group C were recovered most rapidly. Compared with Group B, Group C had significant high liver Kiel 67 antigen labeling index (Ki-67 LI) at day 1 post-HTx (P < .05). Ki-67 LI in groups B and C was higher than that in groups A and D at days 5 and 7 post-HTx. In conclusion, intraperitoneal transplantation of porcine hepatocytes cultured with PLA-O-CMC nanoparticles and embedded in collagen gel can promote significantly liver regeneration in ALF rats.