Use of Hepatocytes in Adhesion and Suspension Cultures for Liver Support Bioreactors

Abstract
Hepatocyte cultivation in bioreactors for hybrid liver support systems is possible under two conditions: attached to a substrate like membranes or microcarriers or in suspension culture. To compare the ammonia metabolism of hepatocytes cultivated under these two conditions, cultures of primary seeded rat hepatocytes were cultivated either attached to collagen coated tissue culture plastic or as a suspension culture. During the time course of culture, the ability of hepatocytes to reduce the ammonia content of the medium decreased in both adhesion and suspension cultures, though to different extents. In suspension cultures, ammonia content was reduced from 350 μM to about 100 μM (day 4) and to about 180 μM (day 6). No significant reduction was seen on day 8 of culture. In contrast, hepatocytes attached to collagen coated dishes remained viable and functional for at least 8 days after plating, reducing ammonia content from 350 μM to 70 μM (day 4), 90 μM (day 6) and 180 μM (day 8). The period of useful metabolism of hepatocytes in bioreactors for hybrid liver support systems appears to depend on the culture conditions