Table 1.

Characteristics of various potential cell sources

Cell type	Usage	Benefits	Limitations and risks
Primary human hepatocytes	Cell transplantation	Compatibility	Limited availability, Difficult isolation, Poor in-vitro multiplication
			Rapid functional deterioration
Porcine hepatocytes	Bioartifical liver	Availability	Functional deterioration in vitro
			Limited biocompatibility
			Immunogenicity
			Risk of xenozoonoses
Cell lines
Tumor-derived cell lines	Bioartifical liver	Unlimited expansion potential	Low functional activity
Immortalized cell lines			Possible tumorigenic activity
Human fetal hepatocytes	Cell transplantation	Extensive in vitro proliferation	Ethical issues
			Limited availability
			Possible tumorigenicity
Oval cells	Cell transplantation	Bi-potent, Liver stem cell	Controversy over existence
Stem cells
Embryonic stem cells	Cell transplantation	Pluripotency, Proliferation capacity	Lack of standardized protocol for obtaining scalable amounts of differentiated cells Poor understanding of differentiation process
Mesenchymal stem cells
Induced-pluripotent stem cells
Induced hepatocyte-like cells	Needs more investigation	Bypassing complicated steps	Functional stability and safety not proven
		Autologous source
		Less tumorigenic