Characterization of the collagen–vinyl graft copolymers prepared by the ceric ion method. II. Infrared spectra and electron microscopy

Abstract

Collagen powder and goat skins were grafted with different vinyl monomers using the ceric ion technique. The graft copolymers were characterized by infrared spectra and electron microscopy. The collagen–vinyl graft copolymers were hydrolyzed by both acid and enzymatic hydrolysis, and the grafted vinyl polymer side chains were isolated. In the grafted poly(methyl methacrylate) (PMMA) side chains isolated by acid hydrolysis, the characteristic amide absorption bands at 1550 and 1660 cm^-1 were not seen prominently. However, in PMMA side chains isolated by enzymatic methods, the amide absorption bands were more prominent as these isolated side chain polymers contained longer fragments of the peptide backbone attached to them. Electron-microscopic observations of grafted collagen fibrils and ultrathin sections of grafted goat skin fibrils did not show any cross-striations. These various evidences indicate that the polymers formed on collagen have penetrated into the fibrils and that they were chemically bound to the collagen molecules.