Fabrication and Hemocompatibility Evaluation of a Robust Honeycomb Nanostructure on Medical Pure Titanium Surface

Thrombosis induced by blood-contacting medical devices is still a major clinical problem, resulting in some serious complications such as infarction, irreversible tissue damage, and even death. Therefore, seeking an effective and safe surface modification approach to improve the hemocompatibility of the material is still urgent. In this research, a novel and facile approach was proposed to fabricate a robust honeycomb nanostructure on medical pure titanium surface by two-step anodic oxidation, which effectively enhanced the physicochemical performance and hemocompatibility of the material. Especially, the honeycomb nanostructure that underwent annealing treatment at 500 °C (HN-Ti-500 °C) presented significant performance to suppress the coagulation cascade in the in vitro tests, the reason mainly ascribed to an overall repulsive interaction between the protein molecule related to thrombosis and material surface based on an extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory analysis. Furthermore, a vessel stent fabricated by HN-Ti-500 °C was implanted into the left carotid artery of rabbits for 1 month. The antithrombotic mechanism and biocompatibility of the modified surface were further verified. The results presented that no thrombus generated and adhered onto the inner surface of the modified stent, and no obvious disorder hyperplasia and inflammation were observed in the intima tissue of the vessel at the implantation site, which indicated that the modified surface could effectively decrease the risk of in-stent restenosis and thrombosis. This work offers a promising strategy for surface modification of blood-contacting medical titanium material to address the clinical complications associated with restenosis and thrombosis.