Regenerex is developing an extracorporeal liver assist device (ELAD) to provide temporary assistance to patients in acute liver failure. The basic technology was developed at the University of Minnesota and has been licensed by the Company. This bioartificial liver employs porcine hepatocytes entrapped in a collagen matrix within the lumens of a hollow-fiber bioreactor. The FDA has approved a Phase I Clinical Trial for the first generation of ELAD at the University of Minnesota. A continuing major challenge in ELAD development will be to maximize hepatocyte function while minimizing bioreactor size. Minimizing blood volume in any extracorporeal therapy is important and is even more so in liver failure patients since they will be hemodynamically unstable. By allowing hepatocytes to form spheroids, long term viability is improved and liver-specific functions, including albumin synthesis and P450 functions are significantly enhanced. This phase I research is to develop a method of forming porcine hepatocytes spheroids suitable for large scale operation and to evaluate the performance of such spheroids in ELAD. A successful Phase I will lead to a Phase II Grant to develop a pilot manufacturing process of the improved ELAD bioreactor for use in large animal pre-clinical trials and eventually clinical application.