The proposed studies are directed toward realizing the outstanding potential of plasma (radiofrequency glow discharge) synthesis methods for preparing new biomedical interface materials. Successful ultrathin interface materials will enable significant improvements to be made in the biological function, and/or the blood and soft-tissue compatibilities of existing biomedical materials. The optimum bulk properties of existing biomaterials are rarely coincident with optimum surface (interface) properties. Consequently, any improvement is dependent upon the ability to optimize the material's surface without adversely affecting its bulk properties. Surface modification through plasma synthesis is a surface specific approach inherently suitable for achieving these goals, with a wide range of blood or soft-tissue contacting materials. Specifically, we propose to (1) synthesize hyrdrophobic and hydrophilic ultrathin (less than 0.5 mu M) coatings for use as interface materials on biomedical substrates which include metals, semicrystalline plastics, and elastomers; (2) evaluate the potential of plasma synthesis methods for preparing surfaces with specific chemical functionalities, such as amines and carboxyl groups, appropriate for immobilizing specific molecules to create novel bioactive biomaterials; and (3) evaluate the in vitro bioactivity, in vitro blood compatibility, and in vivo biocompatibility of surface modified materials. Each of the synthesized novel surfaces on different substrates will undergo comprehensive physical and chemical characterizations. This will enable each surface to be optimized through the adjustment of the plasma reaction conditions. With the emphasis of the proposed studies focused on investigating the fundamental and basic research aspects of the approach, it is anticipated that this will lead ultimately to a significant number of discoveries, innovations and methodologies that will be transferrable readily to a variety of biomedical prosthetic devices.
