? Materials have been developed with bulk physical properties needed for medical devices functioning in the human body. Major emphasis is now being placed on surface chemistry for implantable medical devices to provide biocompatibility with the living tissue and lubricity for safety and ease of implantation. Radical-based surface modification has been developed to the point of rapid growth in commercial availability (PhotoLink coatings based on triplet carbonyl photochemistry). These surface modification energy sources are not effective for the inner surfaces of """"""""opaque"""""""" medical devices such as central venous access and hemodialysis catheters and hollow fiber membranes. This project is designed to further develop latent-reactive radical generators activatible with thermal energy, which readily penetrates these """"""""opaque"""""""" medical devices. The Phase II aims include optimization of the new reagents of Phase I, for bonding hydrophilic blood compatible polymers to biomaterials (e.g. polypropylene, polyurethane, silicone rubber). The use of these new heterobifunctional reagents will be demonstrated for 1) incorporating into the soluble polymer derivative followed by thermo chemical coupling to the surface and 2) activating the biomaterial surface, followed by coupling to soluble polymer derivatives. This innovative approach to activation of radical generators is expected to facilitate the surface modification of """"""""inert"""""""" medical devices, which cannot be activated with long-wavelength photons for external light sources. ? ?
