B. A. Jeffery, M. S. Peppler, A. G. McDonald, University of Alberta, Edmonton, AB, Canada; R. S. Lima, National Research Council of Canada, Boucherville, QC, Canada
Titanium dioxide (TiO2) has been shown to exhibit photocatalytic bactericidal activity. This preliminary study focuses on examining the photocatalytic activity of high velocity oxy-fuel (HVOF) sprayed and flame sprayed (FS) nano-structured TiO2 coatings to kill Pseudomonas aeruginosa (PAK). The HVOF TiO2 coatings were lightly polished and sterilized in preparation for treatment. Plates of PAK were grown, and then suspended in a phosphate buffer saline (PBS) solution. The concentration of bacteria used was regulated by a photospectrometer, which measured the amount of light absorbed by the bacteria-filled solution. This solution was diluted and pipetted onto the prepared sample, then exposed to light. In preliminary tests it was found that, when exposed to white light, 10% of the bacteria were killed after 60 minutes. Exposure to long wavelength (360 nm) UV radiation killed 25% of the bacteria after 60 minutes. These results show that thermal-sprayed nanostructured TiO2 exhibit photocatalytic bactericidal activity.
Summary: A preliminary study testing the photocatalytic bactericidal effects of HVOF-sprayed nanostructured titania coatings on Pseudomonas aeruginosa under white light and UV light.