Materials have been developed with bulk physical properties needed for medical devices functional in the human body. Major emphasis is now being placed on surface chemistry for implantable medical devices to provide biocompatibility with the living tissue, as well as lubricity for safety and ease of implantation. Radical-based surface modification (e.g., RF plasma and photochemical diradical generation) has been successfully developed to the point of rapid growth in commercial availability (e.g., PhotoLink(R) coatings based on triplet carbonyl photochemistzy). These surface modification energy sources are not effective for the inner surfaces of """"""""opaque"""""""" medical devices such as hollow fiber bundle membranes for hemodialysis and blood oxygenation. This project is designed to develop latent-reactive radical generators activatable with external source energy penetrating these """"""""opaque"""""""" medical devices. Phase I aims include thermal activation of new reagents for bonding hydrophilic blood compatible polymers to biomalerials (e.g., polypropylene, polyurethane, silicone rubber). New heterobifunctional reagents will be developed for (1) activating the biomaterial surface, followed by coupling to soluble polymer derivatives, or (2) incorporating into the soluble polymer derivative followed by thermochemical coupling to the surface. This innovative approach to scheduled activation of radical generators is expected to facilitate the coupling to the surfaces of """"""""inert"""""""" biomatezial devices which cannot be illuminated with long-wavelength ultraviolet or visible photons from external light sources.
Hollow fiber bundle hemodialysis and blood oxygenator membranes, luminal surface of opaque catheters, artificial heart, heart valves, and other complex shaped implantable devices constitute an incremental market size of ca. 260 million dollars, not subject to surface modification with current commercial coating technology.
