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Polyurethane membrane as an efficient immobilization carrier for high-density culture of rat hepatocytes in the fixed-bed reactor

2000; Wiley; Volume: 70; Issue: 2 Linguagem: Inglês

10.1002/1097-0290(20001020)70

1097-0290

Hiroshi Kurosawa, Kouichirou Yasumoto, Tetsuhiro Kimura, Yoshifumi Amano,

Clinical Nutrition and Gastroenterology

A fixed-bed bioreactor with a polyurethane membrane (PUM) as a cell-supporting material was developed for high-density culture of rat hepatocytes. The PUM has a heterogeneous porous structure of micropores (pore size 100 μm) with a porosity of 90%. One important feature of a PUM is that the macropores have finger-like structures and their diameters gradually decrease from the upper to the lower layer of the PUM. Most rat hepatocytes were readily immobilized in the micropores of PUM. Immobilized cell densities of 1–3 × 107 cells/cm3 PUM were achieved within 5 min by natural downflow of cell suspension and their immobilization efficiencies were more than 99%. Using a syringe pump, a cell density of 5 × 107 cells/cm3 PUM was achieved with more than 96% immobilization efficiency. Perfusion cultures using this reactor were performed for 7 days without cell leakage. The optimal cell density for albumin secretion was between 2 × 107 and 3 × 107 cells/cm3 PUM. Albumin secretion in the perfusion culture was maintained for a relatively long period of time when compared to that in the monolayer culture. The rate of albumin secretion in the perfusion culture was about 50% of that in monolayer culture. Hepatocytes immobilized in PUM were slightly aggregated, but they maintained spherical form individually even after 7 days of cultivation. The above results show that PUM is a promising cell-supporting material for efficient immobilization of high cell density of hepatocytes. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 70: 160–166, 2000.