Developments in bioartificial liver research: concepts, performance, and applications

As an alternative to liver transplantation, numerous researchers have been working toward the goal of development of a fully functional artificial liv er. In recent years, artificial liver support systems have been advocated a s interim treatments for patients awaiting hepatocyte replacement therapy o r liver transplantation; so-called "bridging" treatments. It is recognized that an effective artificial liver system requires: (1) a viable and highly functional hepatocyte cell line, (2) a suitable bioreactor environment and peripheral control systems, and (3) an effective extracorporeal circulator y system to incorporate an artificial liver system. Conventional systems ha ve, however, suffered from various drawbacks, including incompatibility of cell cultures derived from non-human cells, insufficient cell proliferation , rapid deterioration of cellular function due to an impoverished cellular environment, and lack of system scalability. A newly established artificial liver system overcomes many of these problems and demonstrates a long-term capacity to maintain multiple liver-specific functions, such as protein sy nthesis, enzyme activity, and drug metabolism, both quantitatively and qual itatively. The present review provides an overview of the concepts underpin ning artificial liver systems, the performance of presently available syste ms and the practical applications of available systems and those in develop ment.