IMPROVEMENT OF METABOLIC PERFORMANCE OF HEPATOCYTES CULTURED IN-VITROIN A PACKED-BED REACTOR FOR USE AS A BIOARTIFICIAL LIVER

A packed-bed reactor using reticulated polyvinyl formal (PVF) resin as a support material is a useful configuration to achieve high density culture of hepatocytes for use as a bioartificial liver. The authors i nvestigated the effects of oxygen concentrations of the culture medium on the metabolic performance of hepatocytes cultured in the reactor. A packed-bed reactor loaded with 250 PVF resin cubes (2 x 2 x 2 mm) wa s used. Hepatocytes obtained from male Wistar rats were inoculated int o the reactor. Culture medium was perfused from the reservoir into the reactor through an oxygenator using a roller pump. Concentration of t he dissolved oxygen in the medium was controlled by changing the gas m ixture ratio supplied to the oxygenator. Hepatocytes cultured in the p acked-bed reactor (cell density: 8.6 x 10(6) cells/cm(3) PVF) under co nditions of high dissolved oxygen concentrations ranging from 260 to 4 60 mu mol/L showed 30% higher ammonium metabolic activity and 85% high er albumin secretion activity compared with those from the monolayer c ulture in the earlier culture stage (up to 2 days). However, low oxyge n concentrations in the medium (<100 mu mol/L) impaired activities of cultured hepatocytes.