Fibrinogen adsorption study on ultrananocrystalline diamond as a biocompatible and antithrombogenic interfacial material for implantable devices

Abstract

In this work, we have demonstrated that ultrananocrystalline diamond (UNCD®) film, has significantly lower fibrinogen adsorption than the conventional implantable materials and other diamond types, nanocrystalline or microcrystalline diamond films. In addition, we developed a hot hydrogen treatment in a hot filament chemical vapor deposition (CVD) system, to realize a hydrogen terminated (H-terminated) UNCD surface. The change in surface termination of H-terminated surfaces was characterized by contact angle measurements. Fibrinogen adsorption studies were conducted on three different types of UNCD surfaces: as-deposited, oxidized, and hydrogenated using florescence microscopy. The results reveal that H-terminated UNCD surface has the lowest fibrinogen adsorption, which suggests an excellent biocompatibility and anti-thrombogenicity. The authors have also studied the stability of the H-termination UNCD surface in dynamic fibrinogen-NaHCO3 solution for 2 weeks and in air for half year, no surface chemistry change was observed from both cases.