Implantation of a
drug-eluting stent is the most common treatment method for patients with cardiovascular
atherosclerosis. However, this treatment may delay re-endothelialization, and the
drug polymer-coated
stent may induce
thrombosis months after a
stent implantation. The development of
polymer-free
drug-eluting stents is a promising approach to overcome these shortcomings.
Titanium dioxide nanotubes (TiO2-NTs) are excellent
drug carriers and have been considered as a potential material for
polymer-free
drug-eluting stents. However, TiO2-NTs reportedly induce severe blood clotting, which is a significant shortcoming for use as a
stent. Vascular
stents must be compatible with blood and must have antibacterial, anti-inflammatory, and selective inhibitory activities in the abnormal
hyperplasia of smooth muscle cells, instead of delaying the re-endothelialization of endothelial cells. To meet these requirements, we presented a composite material that featured ultraviolet (UV) irradiation of TiO2-NTs-containing
silver nanoparticles (AgNPs). The AgNPs were loaded in the lumen of TiO2-NTs as a representative compound to suppress the inflammatory response and
hyperplasia. UV irradiation was performed as a novel method to improve the
anticoagulant ability of the AgNP-loaded TiO2-NTs. The chemical state and biocompatibility of the UV-TiO2-NTs@AgNPs were evaluated. UV irradiation strongly improved the
anticoagulant ability of the TiO2-NTs and moderated the release of Ag+ from AgNPs, which selectively suppressed the inflammatory response and
hyperplasia. Furthermore, the UV-TiO2-NTs@AgNPs-2 displayed enhanced biocompatibility evidenced by the inhibition of platelet adhesion, bactericidal activity, selective suppression of the smooth muscle cell proliferation, and inhibition of the adhesion of macrophages. The collective findings indicate the potential of the photofunctionalized TiO2-NTs loaded with AgNPs as a material for
polymer-free
drug-eluting stents.