Toward new biomaterials

Polymers are widely used for a large range of medical devices used as bioma terials on a temporary, intermittent, and long-term basis. II is now well a ccepted that the initial rapid adsorption of proteins to polymeric surfaces affects the performance of these biomaterials. However, protein adsorption to a polymer surface can be modulated by an appropriate design of the inte rface. Extensive study has shown that these interactions can be minimized b y coating with a highly hydrated layer (hydrogel), by grafting on the surfa ce different biomolecules, or by creating domains with chemical functions ( charges, hydrophilic groups). Our laboratory has investigated the latter ap proach over the past 2 decades, in particular the synthesis and the biologi cal activities of polymers to improve the biocompatibility of blood-contact ing devices. These soluble and insoluble polymers were obtained by chemical substitution of macromolecular chains with suitable groups able to develop specific interactions with biological components. Applied to compatibility with the blood and the immune systems, this concept has been extended to i nteractions of polymeric biomaterials with eukaryotic and prokaryotic cells . The design of new biomaterials with low bacteria attachment is thus under intensive study. After a brief overview of current trends in the surface m odifications of biocompatible materials, we will describe how biospecific p olymers can be obtained and review our recent results on the inhibition of bacterial adhesion using one type of functionalized polymer obtained by ran dom substitution. This strategy applied to existing or new materials, seems promising for thr limitation of biomaterial-associated infections (Infect Control Hosp Epidemiol 2000;21: 104-110).