HOLLOW-FIBER BIOARTIFICIAL LIVER UTILIZING COLLAGEN-ENTRAPPED PORCINEHEPATOCYTE SPHEROIDS

A xenogeneic hollow fiber bioreactor utilizing collagen-entrapped disp ersed hepatocytes has been developed as an extracorporeal bioartificia l liver (BAL) for potential treatment of acute human fulminant hepatit is. Prolonged viability, enhanced liver-specific functions, and differ entiated state have been observed in primary porcine hepatocytes culti vated as spheroids compared to dispersed hepatocytes plated on a monol ayer. Entrapment of spheroids into the BAL can potentially improve per formance over the existing device. Therefore, studies were conducted t o evaluate the feasibility of utilizing spheroids as the functionally active component of our hybrid device. Confocal microscopy indicated h igh viability of spheroids entrapped into cylindrical collagen gel. En trapment of spheroids alone into collagen gel showed reduced ability t o contract collagen gel. By mixing spheroids with dispersed cells, the extent of collagen gel contraction was increased. Hepatocyte spheroid s collagen-entrapped into BAL devices were maintained for over 9 days. Assessment of albumin synthesis and ureagenesis within a spheroid-ent rapment BAL indicated higher or at least as high activity on a per-cel l basis compared to a dispersed hepatocyte-entrapment BAL device. Clea rance of 4-methylumbelliferone to its glucuronide was detected through out the culture period as a marker of phase II conjugation activity. A spheroid-entrapment bioartificial liver warrants further studies for potential human therapy. (C) 1996 John Wiley & Sons