Blood compatibility of sputter-deposited alumina films.

The surface modification of metals by the application of blood compatible ceramics is one approach to developing durable and blood-compatible materials. The blood compatibility of sputter-deposited alumina films was investigated in vitro. The alumina films were prepared by reactive sputtering and conventional sputtering. Diffractometer studies of the alumina films indicate that the sputter-deposited alumina films have amorphous structures. Electron spectroscopy chemical analysis studies of the alumina films indicate that the sputter-deposited alumina films are nonstoichiometric (O/A1 ratio of 1.15-1.66). We examined the platelet reaction to the alumina films and the intrinsic coagulation factor XII activation by the alumina films. Medical grade segmented polyurethane was also tested. The alumina films experienced an adhesion of about 50% fewer platelets than the segmented polyurethane. Also, fewer platelet morphologic changes were observed on the alumina films than on the segmented polyurethane. Factor XII activation was less on the alumina films than on the segmented polyurethane. Surface modification by the sputter-deposited alumina films is promising for developing blood-compatible and durable materials.