Antibacterial nano-structured titania coating incorporated with silver nanoparticles

Abstract

Titanium (Ti) implants are widely used clinically but post-operation infection remains one of the most common and serious complications. A surface boasting long-term antibacterial ability is highly desirable in order to prevent implant associated infection. In this study, titania nanotubes (TiO 2-NTs) incorporated with silver (Ag) nanoparticles are fabricated on Ti implants to achieve this purpose. The Ag nanoparticles adhere tightly to the wall of the TiO 2-NTs prepared by immersion in a silver nitrate solution followed by ultraviolet light radiation. The amount of Ag introduced to the NTs can be varied by changing processing parameters such as the AgNO 3 concentration and immersion time. The TiO 2-NTs loaded with Ag nanoparticles (NT-Ag) can kill all the planktonic bacteria in the suspension during the first several days, and the ability of the NT-Ag to prevent bacterial adhesion is maintained without obvious decline for 30 days, which are normally long enough to prevent post-operation infection in the early and intermediate stages and perhaps even late infection around the implant. Although the NT-Ag structure shows some cytotoxicity, it can be reduced by controlling the Ag release rate. The NT-Ag materials are also expected to possess satisfactory osteoconductivity in addition to the good biological performance expected of TiO 2-NTs. This controllable NT-Ag structure which provides relatively long-term antibacterial ability and good tissue integration has promising applications in orthopedics, dentistry, and other biomedical devices.