Photofunctionalized and Drug-Loaded TiO2 Nanotubes with Improved Vascular Biocompatibility as a Potential
Material for Polymer-Free Drug-Eluting Stents
posted on 2020-03-31, 19:49authored bySheng Dai, Lang Jiang, Luying Liu, Jiang Chen, Yuzhen Liao, Shuang He, Jiawei Cui, Xiaoqi Liu, Ansha Zhao, Ping Yang, Nan Huang
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.