Interpenetrating polymer networks for biological applications.

The use of a sequential polymerization method for preparing interpenetrating polymer networks with biocomatible surfaces has been studied. A hydrogel monomer was made to undergo polymerization with simultaneous cross-link formation, in the presence of a swollen thermoplastic elastomer heterophase block copolymer. On removal of the swelling solvent, an interpenetrating network of the hydrogel and the thermoplastic elastomer was obtained, which absorbed water in the manner of a hydrogel, but had mechanical properties superior to hydrogels. The studies employed a poly(ether-urethane) block copolymer as the thermoplastic elastomer. The materials fabricated included samples in which the interpenetrating polymerization extended throughout the termoplastic elastomer as well as samples in which the interpenetrating polymerization was confined to a region near the surface of the latter.