Surface characterization of Ca-P/Ag/TiO2 nanotube composite layers on Ti intended for biomedical applications

The new generation of medical implants made by titanium is functionalized with different coatings to improve their bioactivity and reduce a risk of infection. This article describes how these goals can be achieved via deposition of silver nanoparticles and calcium phosphate coating. TiO2 nanotubes were grown on a Ti substrate via electrochemical oxidation at constant voltage in a mixture of glycerol, deionized water, and NH4F. Silver particles with a size of 250 nm were deposited on the surface using the sputter deposition technique. Calcium phosphate coatings were grown on the nanotubular titania by simple immersion in Hanks' solution. It has been found that the silver nanoparticles are distributed homogeneously in the coating, which is promising for maintaining a steady antibacterial effect. The results show also that the Ag-incorporated TiO2 nanotubes significantly stimulate apatite deposition from Hanks' solution. The highly ordered Ag-incorporated TiO2 nanotube arrays with apatite coating may offer unique surface features for biomedical implants, ensuring both biocompatibility and antibacterial properties. (C) 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.