Improved hepatocyte in vitro maintenance in a culture model with woven multicompartment capillary systems: electron microscopy studies.

Primary pig hepatocytes form a tissuelike structure in an in vitro culture model that has provision for three-dimensional cell orientation, cell aggregation, decentralized cell perfusion with low metabolite gradients, integral oxygenation, and nonparenchymal cell coculture. Scanning electron microscopy (SEM) has shown that hepatocytes spontaneously form aggregates in a three-dimensional structure between and on the surface of artificial capillaries. Transmission electron microscopy (TEM) has shown that after 7 weeks of in vitro perfusion, the cell ultrastructure remains similar to that of the parenchyma in vivo. Golgi complexes, active membrane processes, reorganization of cell junctions, and bile canaliculi-like intercellular spaces were demonstrated.