Controlled delivery of dexamethasone from TiO2 film with nanoporous structure on Ti-25Nb-3Mo-2Sn-3Zr biomedical alloy without polymeric carrier

Nanoporous structured TiO2 film on TLM alloy was first fabricated by two-step anodization and used as drug carriers. The nanoporous structured TiO2 film with a thickness of 470 nm was self-organized in electrolyte at a voltage of 30 V, and it possesses higher porosity, smoother surface and better adhesion with TLM alloy matrix compared with TiO2 nanotube prepared by one-step anodization. At the same time, it has better hydrophily than TLM alloy matrix. Dexamethasone (DXM) was successfully loaded onto the nanoporous film via a vacuum assisted method, and drug loading amount can be adjusted easily. The nanoporous structured film loaded with DXM has presented excellent sustained drug release effect, and kept intact microstructure after drug release in vitro test, indicating that TLM alloy coated with nanoporous TiO2 film has potential application in polymer-free drug eluting stents.