Antibacterial properties of nanostructured silver titanate thin films formed on a titanium plate.

Antibacterial activity of various surfaces against methicillin-resistant Staphylococcus aureus (MRSA) was studied. Sodium titanate thin film with a porous network structure and sodium titanate nanotube thin film were formed on titanium surfaces through the reaction of titanium plates with NaOH solutions. Through a silver ion-exchange treatment, Na(+) ions in sodium titanate were exchanged with Ag(+) ions in silver acetate solution, along with the loading of silver nanoparticles on the titanate surfaces. Results of silver ion elution tests of the thin films in fetal bovine serum solution indicate that the release period and the number of silver ions released from the silver titanate thin films can be controlled by altering the crystal structure, nanostructure, and thickness of the titanate phase. The silver ion-exchanged titanate thin films showed high antibacterial activity against MRSA. It was also revealed that although the crystal structure of titanate itself has no large antibacterial effect, higher antibacterial activity mainly arises from the silver ions held in the interlayer spacing of the titanate. The obtained results should aid the development of more convenient and inexpensive antibacterial implants. (c) 2009 Wiley Periodicals, Inc.