Principles of hepatocyte repopulation.

Hepatocyte transplantation (HTx) is technically feasible and can be clinically beneficial. Current research focuses on optimizing parameters which relate to the outcome of HTx, including site of transplantation, cell number and, most notably, the preferred cell type to be transplanted (differentiated adult vs. fetal hepatocytes vs. putative progenitor or precursor cells). However, the single major impediment towards the clinical effectiveness of HTx is the limited expansion of donor cells in the recipient liver. To this end, a relative growth advantage must be present or is to be imposed on transplanted hepatocytes versus resident cells. Possible strategies are presented and discussed.