In vitro investigation of hemocompatibility of hydrophilic SiN_x: H films fabricated by plasma-enhanced chemical vapor deposition

SiN_x:H films with different N/Si ratios were synthesized by plasma-enhanced chemical vapor deposition (PECVD), aimed for BioMEMS or other biomedical applications. In vitro platelet adhesion tests were conducted to evaluate the hemocompatibility of the prepared films and the results were compared to low-temperature isotropic carbon (LTI-C) which is the most commonly used materials in commercial blood contacting biomedical devices such as artificial heart valves. Our results indicate that the SiN_x:H films offer acceptable hemocompatibility compared to LTI-C and possess better characteristics. The hydrophilic property in terms of surface free energy is considered to contribute to the platelet adhesion and activation behavior. The thrombogenicity of the materials is investigated from the thermodynamic and kinetic points of view. Our results indicate that the Si-N bonds play a crucial role in determining the hydrophilic property of the film and consequently affect the blood/surface reactions and hemocompatibility of the films. © 2005 Elsevier B.V. All rights reserved.