Controlled and localized drug delivery using Titania nanotubes

Titanium-dioxide nanotubes (TNTs) were fabricated by anodic oxidation of titanium (Ti) substrate and loaded with ciprofloxacin. A thin layer of Poly Lactic-co-Glycolic Acid (PLGA) was coated on top of the drug-loaded TNTs at various thicknesses. Field Emission Scanning Electron Microscopy (FESEM) was used to characterize the developed substrate. The FESEM images of anodized samples showed that, the native oxide layer on the surface of the Ti substrate was replaced with an array of ordered nanotubes up to ~700 nm in length. Drug release studies of ciprofloxacin were conducted in Phosphate Buffered Saline (PBS) solution for 24 h. The studies showed the ability of PLGA to slow down the drug release rate, depending on the thickness of the deposited layer. MG-63 cells (human osteosarcoma cell lines) were cultured on the TNT substrates after loading ciprofloxacin and coating with various concentrations of PLGA to show the potentiality for better osseointegration. An MTT assay was carried out to study cell viability and proliferation on these substrates. Anti-microbial studies were carried out to demonstrate the release of ciprofloxacin in treating infections against Staphylococcus epidermidis. These in-depth studies showed that local concentration of the drug released could be controlled by varying the thickness of the PLGA layer to allow for better implant osseointegration and treatment of bone infections.