Antithrombogenic investigation of surface energy and optical bandgap and hemocompatibility mechanism of Ti(Ta(+5))O2 thin films.

Recent improvements in the antithrombogenic properties of blood contacting biomaterials permit a hybrid design of layers for biomedical applications such as artificial heart valves and stents. Using magnetron sputtering and thermal oxidation, titanium oxide thin films containing tantalum. Ti(Ta(+5))O2, are fabricated to meet the challenge of enhanced hemocompatibility. The blood compatibility is evaluated in vitro by clotting time and platelet adhesion measurement, and in vivo experiments are also conducted. The Ti(Ta(+5))O2 films exhibit attractive blood compatibility exceeding that of low isotropic pyrolytic carbon. Physical properties such as surface energy and semiconductivity are found to play important roles. Our calculated results reveal that the smaller surface force gamma(s) of the film and the smaller blood film interfacial tension gamma(c,blood) are partially responsible for the enhancement of the blood compatibility. Based on the optical bandgap model, the film possesses better hemocompatibility because its optical bandgap of 3.2 eV is wider than that of fibrinogen having a bandgap of 1.8 eV. These factors result in thinner protein layers on the film surface, less protein denaturing, and overall excellent antithrombogenic properties.

[1]  Yi Jin,et al.  In vitro investigation of blood compatibility of Ti with oxide layers of rutile structure. , 1994, Journal of biomaterials applications.

[2]  Mutaz B. Habal,et al.  Biomaterials and Bioengineering Handbook , 2001 .

[3]  Xianghuai Liu,et al.  Blood compatibility of amorphous titanium oxide films synthesized by ion beam enhanced deposition. , 1998, Biomaterials.

[4]  N. Huang,et al.  In vitro investigation of blood compatibility of Ti with oxide layers of rutile structure. , 1994 .

[5]  Donald L. Wise,et al.  Biomaterials and Bioengineering Handbook , 2000 .

[6]  A. Bolz,et al.  Artificial heart valves: improved blood compatibility by PECVD a-SiC:H coating. , 1990, Artificial organs.

[7]  Takeo Matsumoto,et al.  Development of a Ceramic Heart Valve , 1989, Journal of biomaterials applications.

[8]  C. P. Sharma,et al.  Titanium-Protein Interaction: Changes with Oxide Layer Thickness , 1991, Journal of biomaterials applications.

[9]  G. Huth,et al.  Modern Bioelectrochemistry , 1986, Springer US.

[10]  Buddy D. Ratner,et al.  Biomaterials Science: An Introduction to Materials in Medicine , 1996 .

[11]  N. F. Mott,et al.  Conduction in non-crystalline materials: III. Localized states in a pseudogap and near extremities of conduction and valence bands , 1969 .

[12]  F. Silver,et al.  Biomaterials Science and Biocompatibility , 1999, Springer New York.

[13]  N. Rushton,et al.  Biocompatibility of diamond-like carbon coating. , 1991, Biomaterials.

[14]  P. Nikolopoulos,et al.  Wettability and interfacial interactions in bioceramic-body-liquid systems. , 1995, Journal of biomedical materials research.

[15]  Y. Nosé,et al.  A new method for evalution of antithrombogenicity of materials. , 1972, Journal of biomedical materials research.

[16]  C. Wright,et al.  Handbook of biomaterials evaluation: Scientific, technical, and clinical testing of implant materials , 1987 .

[17]  P. Havlík,et al.  TiN coating: surface characterization and haemocompatibility. , 1993, Biomaterials.

[18]  F. Rouais,et al.  Ex vivo leucocyte adhesion and protein adsorption on TiN. , 1993, Biomaterials.