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

We have constructed a bioreactor aimed at imitating the three-dimensio nal micro- and macroenvironment of the liver. In vivo hepatocytes are arranged in plates of cell monolayers and are specifically attached wi th both sinusoidal surfaces to the space of Disse which contains extra cellular matrix. Nonparenchymal cells are located on the other side of the space of Disse toward the sinusoid. For supporting monolayer hepa tocytes 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 increas es during an adaptive period to the in vitro environment. In contrast to conventional single gel hepatocytes, double gel hepatocytes maintai n expression of sinusoidal microvilli and a polyhedric cell shape in c ulture 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 organot ypical development of a full-sized hybrid artificial liver.