Despite the recent advances in supportive therapies, there is still no direct, satisfactory treatment for endstage liver failure. Orthotopic liver transplantation is the only life-saving treatment currently available for acute liver failure and acute-on-chronic liver disease [4, 12]. However, due to a severe shortage of donor organs, only 25% of patients on waiting lists actually receive a liver transplant and almost 2,000 patients on the waiting lists die each year in the United States (liver waiting list, United Network for Organ Sharing, 2003, available at www. unos.org). Furthermore, nearly 90% of patients with fulminant hepatic failure (FHF) will die unless they receive the transplantation [72]. FHF is a severe form of hyperacute liver failure; it is defined by the appearance of encephalopathy within 8 weeks after the onset of jaundice in a patient without previous known liver diseases. If essential liver functions can be restored during the critical phase of liver failure, by either artificial or auxiliary methods, it might be possible to improve the survival rate of these patients without transplantation. Therefore, more donor livers will be available and costly transplantation procedures can be avoided [24]. Various nonbiological approaches, such as hemodialysis, hemoperfusion, plasmapheresis, and plasma exchange, have had a limited success because of the insufficient replacement of the synthetic and metabolic functions of the liver in these systems [16, 38, 60, 92]. On the other hand, extracorporeal biological treatments including whole-liver perfusion, liver-slice perfusions, and cross hemodialysis, have shown some beneficial results, but they are difficult to implement in a clinical setting [5, 62, 77].