Transplantable Liver Organoids, Too Many Cell Types to Choose: a Need for Scientific Self-Organization

Purpose of Review Liver stem cells have been proposed as alternatives or additions for whole liver transplantations to accommodate the donor liver shortage. Various sources of liver stem cells have been described in experimental animal studies. Here we aim to compare the various studies. Recent Findings Irrespective of the experimental design, the percentage of long-lasting survival and functional recovery of transplanted cells is generally very low. An exception to this are the proliferating hepatocytes transplanted into Fah(-/-) Rag2(-/-)IL2rg(-/-) mice; here 4-month post-transplantation around 65% repopulation was observed, and 11/14 mice survived in contrast to zero survival in sham-treated animals. Taking the different cellular sources for the organoids, the different maturation status of the transplanted cells, and the variable animal models into account, a paper-to-paper comparison is compromised. This lack of objective comparison restricts the translation of these model studies into clinical practice.