In vitro function of porcine hepatocyte spheroids in 100% human plasma.

To assess their functional stability, porcine hepatocyte spheroids, which have great potential in bioartificial liver systems and/or xenogeneic liver transplantation, were cultured in vitro in 100% human plasma, and their ammonium detoxification capacity was measured. In a short-term functional study, collagen-gel entrapped and rotationally cultured porcine hepatocyte spheroids showed almost the same functional expression, which was approximately twice that of monolayers. No significant functional deterioration was observed up to day 10 as compared with those in a synthesized medium without collagen gel entrapment. In a longer term study (4 wk) using rotational culture, morphological and functional deterioration presumably due to immunorejection involving complement proteins and natural antibodies progressed gradually with culture time. On the termination of the culture, the detoxification ability for the residual cells was approximately two-thirds that on day 2.