Photofunctionalized TiO₂-TiN micropattern coating with anticoagulant properties and ECs contact-guidance effect

Titanium nitride (TiN) and titanium dioxide (TiO₂) are two titanium-based coatings commonly used in cardiovascular stent surface engineering. Generally, TiN has good mechanical properties and endothelial cell (ECs) compatibility but poor anticoagulant properties and cannot modulate cell growth orientation and morphology. TiO₂ has excellent corrosion resistance and biosafety. Besides, TiO₂ has the photocatalytic anticoagulant property, which can migrate to other materials tens of microns away. Based on the above properties, a striped TiO₂-TiN micropattern coating was designed and fabricated in this study, and the coating was photofunctionalized by UV irradiation. The obtained photo-functionalized TiO₂-TiN micropattern coating showed anticoagulant properties by the migrating effect of the photocatalytic anticoagulant property of TiO₂. Besides, the TiO₂-TiN micropattern coatings showed ECs compatibility. Furthermore, the growth orientation and cell shape of ECs on TiO₂-TiN samples were effectively regulated by the stripe pattern's contact guidance effect, which was particularly evident on the photo-functionalized TiO₂-TiN samples. We envision that this photofunctionalized TiO₂-TiN striped micropattern coating has significant potential for the surface engineering of vascular stents.