An antimicrobial TiO2 coating for reducing hospital-acquired infection

Titanium dioxide (TiO2) has been developed and applied extensively in the form of coatings, in particular for its unique properties such as non-toxicity, high photocatalytic activity, and strong self-cleaning ability. These coatings, which can be prepared via various processes, have not yet been proved to be antimicrobial. This research involves an arc ion plating method to produce TiO2 film on medical grade AISI 304 stainless steel. Antimicrobial efficacy of the deposits is expected due to the photocatalysis action of the anatase phase presented in the deposit. The performance of the coating is evaluated by a JIS Z2801:2000 industrial standard. Experimental results show that TiO2 film mainly consisting of anatase structure can be prepared with a high growth rate of 5 microm/h. Antimicrobial activity (R) of the deposited TiO2 film against Staphylococcus aureus and Escherichia coli was 3.0 and 2.5, respectively, far beyond the value designated in JIS standard. This provides an effective antimicrobial surface coating method for medical implements thereby reducing the risk of hospital-acquired infections.