A NOVEL BIOREACTOR DESIGN FOR IN-VITRO RECONSTRUCTION OF IN-VIVO LIVER CHARACTERISTICS

We have constructed a bioreactor aimed at imitating the three-dimensional micro- and macroenvironment of the liver. In vivo hepatocytes are arranged in plates of cell monolayers and are specifically attached with both sinusoidal surfaces to the space of Disse which contains extracellular matrix. Nonparenchymal cells are located on the other side of the space of Disse toward the sinusoid. For supporting monolayer hepatocytes with bipolar attachment to the extracellular matrix, we used a double gel culture technique that sandwiches hepatocytes between two layers of collagen. In double gel cultures, albumin production increases during an adaptive period to the in vitro environment. In contrast to conventional single gel hepatocytes, double gel hepatocytes maintain expression of sinusoidal microvilli and a polyhedric cell shape in culture as seen by transmission electron microscopy. Albumin production in the bioreactor was stable. The organotypical bioreactor concept is an example of organ mimicry and may provide the basis for the organotypical development of a full-sized hybrid artificial liver.