Morphofunctional reaction of leukocytes and platelets in in vitro contact with a‐C:H:SiOx‐coated Ti–6Al–4V substrate

Abstract The article deals with the plasma‐assisted chemical vapor deposition of 0.3–1.4 μm thick a‐C:H:SiO x films in a mixture of argon and polyphenylmethylsiloxane vapor onto the Ti–6Al–4V alloy substrate, which is often used as an implant material. The a‐C:H:SiO x film structure is studied by the Fourier‐transform infrared and Raman spectroscopies. The pull‐off adhesion test assesses the adhesive strength of a‐C:H:SiO x films, and the ball‐on‐disk method is employed to measure their wear rate and friction coefficient. According to these studies, a‐C:H:SiO x films are highly adhesive to the Ti–6Al–4V substrate, have low (0.056) friction coefficient and wear rate (9.8 × 10 −8 mm 3 N −1 m −1 ) in phosphate‐buffered saline at 40°C. In vitro studies show neither thrombogenicity nor cytotoxicity of the a‐C:H:SiO x film for the human blood mononuclear cells (hBMNCs). The in vitro contact between the hBMNC culture and a‐C:H:SiO x films 0.8–1.4 μm thick deposited onto Ti–6Al–4V substrates reduces a 24‐hour secretion of pro‐inflammatory cytokines and chemokines IL‐8, IL‐17, TNFα, RANTES, and MCP‐1. This reduction is more significant when the film thickness is 1.4 μm and implies its potential anti‐inflammatory effect and possible application in cardiovascular surgery. The dependence is suggested for the concentration of anti‐inflammatory cytokines and chemokines and the a‐C:H:SiO x film thickness, which correlates with the surface wettability and electrostatic potential. The article discusses the possible applications of the anti‐inflammatory effect and low thrombogenicity of a‐C:H:SiO x films in cardiovascular surgery.