Growth enhancement of anchorage-dependent and anchorage-independent cells by coimmobilization of insulin with poly(allylamine) or gelatin.

An anchorage-dependent cell, mouse fibroblast STO cell and an anchorage-independent cell, K562 cell, were cultured on a polymer membrane coimmobilized with insulin and adhesion factors, poly(allylamine), and gelatin. The former is cationic and electrostatically (non-biospecifically) enhances cell adhesion, and the latter is a hydrolyzate of collagen and biospecifically enhances cell adhesion. They were immobilized onto a surface-hydrolyzed poly(methyl methacrylate) membrane by water-soluble carbodiimide. The adhesion of both STO and K562 cells was accelerated by the immobilization of poly(allylamine) or gelatin. The insulin immobilization did not affect adhesion of either cell. Although the growth of STO cells was enhanced on the insulin-immobilized membrane, the growth of K562 cells was not. However, the coimmobilizaiton of insulin and a cell-adhesion factor accelerated growth of both cells. It was considered that an increased frequency of interaction between the immobilized insulin and the receptor led to the cell growth acceleration.