Mechanism Of Antithrombotic Properties Of Two Kinds Of Blood-contacting Inorganic Films

The principal problem associated with blood-contacting biomedical device and artificial organs is thrombogenesis. A desire to overcome thrombogenesis caused by implantation of artificial devices has prompted researchers to develop new materials and improved approaches. Surface modification has been shown to be one significant method to improve anticoagulation of conventional biomaterial contact with blood. Many different kinds of inorganic films have been investigated as candidate materials for the coatings. However, very few of the coatings have been reported to possess better hemocompatibility than low temperature isotropic pyrolytic carbon (LTIC), though its hemocompatibility is still far from ideal. One important reason is that these inorganic films are transplanted from the other research fields. Thus, the understanding for their thromboresistance mechanism is not sufficient and urgently requires further investigation.In order to reveal the thromboresistance mechanism of inorganic films, we focus our attention in this work on the relations between the thromboresistance behavior and the structure and properties of representative inorganic films, Ti-O system film and carbon base film engaging many researchers' attentions. Ti- O thin films doped with phosphorus, amorphous carbon thin films (a-C:H) and nitrogen incorporated amorphous carbon thin films (a-C:N:H) were synthesized by ion implantation and plasma immersion ion implantation-deposition (PIII-D). Their chemical composition and structural information were determined using Rutherford backscattering spectrometry (RBS), elastic recoil detection (ERD), X-ray photoelectron spectroscopy (XPS) and its valence band spectroscopy (VXPS), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). Their anti-coagulant properties are evaluated using the in vitro and in vivo tests. The interaction behavior at the interface between the biomaterial films and the bioactive phases such as plasma proteins and blood cells in human blood is also investigated using the biochemistry examinations for reference. The following conclusions are obtained according to the current thrombosis theory, the theory about solid surface...