Effect of Calcium and Strontium on Mesoporous Titania Coatings for Implant Applications

Increasing interest in the role of ions such as calcium and strontium in bone formation has called for the investigation of multifunctional ion-doped implant coatings. Mesoporous titania coatings incorporating calcium or strontium enabled a unique pore morphology and potential for drug delivery. Coatings were produced on titanium by an evaporation in duced self-assembly method with the addition of calcium or strontium to the sol causing a shift in morphology from a hexagonally-packed to a worm-like porous network. Pore sizes ranged from 3.8 - 5 nm and coatings exhibited high sur face areas between 181 - 215.5 m2 /g, as measured by N2 adsorption-desorption. Coatings were loaded with 1 mg/ml Cephalothin, and showed sustained release of the antibiotic over one week in vitro. Cell studies confirmed that the ion addition had no toxic effect on human-like osteoblastic SaOS-2 cells. The results of this study suggest the potential for mesoporous coatings with calcium or strontium incorporation for direct bone-interfacing and combined drug delivery implant applications.