Natural and Long-term Preservable Anticoagulant Property of SiO 2 & TiO 2 Bilayer Films

Xiangqin Liu¹Xiao Chen^2,3Hongrui Jiang¹Xiaoqi Liu¹Xiaoqi Liu³Hong Sun³Qiongjian Huang⁴Ansha Zhao³Nan Huang³Ping Yang^3*Jiang Chen^1*

• ¹Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan Province, China
• ²Shenzhen Longgang Otolaryngology Hospital, Shenzhen, Guangdong Province, China
• ³Southwest Jiaotong University, Chengdu, Sichuan Province, China
• ⁴Chongqing Industry Polytechnic College, Chongqing, China

Titanium dioxide (TiO 2 ) film has been extensively studied as a blood-contacting material. However, the inherent positive charge and the low -OH group on the surface lead to its insufficient natural anticoagulant properties. Besides, due to the high adsorption rate of carbon-containing adsorbates, the natural anticoagulant property of TiO 2 films is rapidly deteriorate during storage. It is challenging to improve the natural anticoagulant property of TiO 2 films and to prolong their storage time. In this study, SiO 2 & TiO 2 bilayer films were fabricated using unbalanced magnetron sputtering by covering the TiO 2 surface with a SiO 2 film with a thickness of about 40 nm. This bilayer film showed unique properties including long-term hydrophilicity, negative charging, low carbon-containing adsorbates adhesion, and high -OH group content. The Si-O-Ti bond formed at the interface of SiO 2 and TiO 2 might response to the above unique properties, which further induced excellent natural anticoagulant properties. After 15 weeks of storage, the platelet surface coverage on the SiO 2 & TiO 2 bilayer film was less than 30% of that on the TiO 2 film. This SiO 2 & TiO 2 bilayer film showed satisfactory natural and long-term anticoagulant properties, and therefore is expected to be an alternative to TiO 2 film for blood-contacting devices.