Covalent immobilization of proteins on to the surface of poly(vinyl alcohol) hydrogel

Covalent immobilization of cell-adhesive proteins such as collagen and fibronectin on to the surface of poly(vinyl alcohol) hydrogel was investigated by using diisocyanates, polyisocyanates, and cyanogen bromide. It was found that 0.5 and 12 micrograms/cm2 of collagen were immobilized on to the surface by using hexamethylene diisocyanate and cyanogen bromide, respectively. The big difference in the graft amount between the two methods was ascribed to the different reaction media employed for the surface modifications; toluene for the reaction with hexamethylene diisocyanate and water for the reaction with cyanogen bromide.