Enhancement of cell growth on a porous membrane co-immobilized with cell-growth and cell adhesion factors.

Insulin was co-immobilized with cell adhesion factors such as fibronectin or polylysine on a porous poly(ethylene terephthalate) membrane. The surface of the poly(ethylene terephthalate) membrane was partially hydrolysed under alkaline conditions and the proteins were immobilized on the membrane surface using a water-soluble carbodiimide. The adhesion of STO mouse fibroblast cells onto the immobilized membrane was accelerated by the immobilization of fibronectin and polylysine. The cell growth was enhanced by immobilization of insulin. Co-immobilization of insulin with the adhesion factors markedly accelerated cell growth. No significant differences were found between the effects of fibronectin and polylysine. The absence of insulin release was confirmed by the fact that growth was no accelerated under essentially the same culture conditions without direct contact with the protein-immobilized membrane.