A new three-dimensional culture system for hepatocytes using reticulated polyurethane.

Poly-N-para-vinylbenzyl-lactonamide (PVLA)-coated reticulated polyurethane (PVLA-RPU) has been employed for the long-term maintenance of primary rat hepatocyte cultures. After 3 days of incubation of 2 x 10(7) hepatocytes/cm3 embedded in PVLA-RPU discs and kept in culture medium, most cells showed typical hepatocyte morphology, with some bile canaliculus-like intercellular spaces among the hepatocytes on examination with scanning and transmission electron microscopy. The cells were attached to the surface of the PVLA-RPU and formed multicellular spheroids in the reticulated pores. The hepatocytes maintained various liver-specific functions such as albumin secretion, ammonium metabolism, urea synthesis and gluconeogenesis, and they were viable. The liver-specific functions could be maintained for more than 1 month when the cells were kept in the rats' peritoneal cavities. This new system may be useful as a bioreactor for an artificial liver.