Abstract
This paper describes a novel approach for obtaining covalent bonding to tissues by chemical grafting of polymeric side chains to the collagenous backbone. Soft tissues such as calfskin or ratskin can be modified by acrylic, methacrylic, or vinyl monomers containing a variety of functional groups using ceric ions, persulfateβbisulfite or comonomers forming donorβacceptor complexes as initiators. Reactions take place within 20 min to 3 hr under experimental condition which, with suitable changes, might be tolerated clinically. The resulting products are insoluble in solvents for the respective homopolymers. It is likely that the polymeric side chain is attached chemically to the collagenous backbone. With ratskin, the grafting takes place mainly at the surface, resulting in a change in wettability and water sorption of the substrate. Modified hydrophilic, hydrophobic or even oil repellent surfaces can be prepared by judicious choice of monomer used. Thus, hydrophobic, oleophobic subdermal ratskin surfaces are obtained on reaction with flourinated monomers. Treated ratskins appear more resistant to fungal attack than the original substrate. It is conceivable that the polymeric side chains can serve as adhesive liners since the modified surface may improve the ability of the substrate to adhere to restorative materials.