title: Antibacterial performance of nanoscaled visible-light responsive platinum-containing titania photocatalyst in vitro and in vivo.
abstract: BACKGROUND
  Traditional antibacterial photocatalysts are primarily induced by ultraviolet light to elicit antibacterial reactive oxygen species. New generation visible-light responsive photocatalysts were discovered, offering greater opportunity to use photocatalysts as disinfectants in our living environment. Recently, we found that visible-light responsive platinum-containing titania (TiO2-Pt) exerted high performance antibacterial property against soil-borne pathogens even in soil highly contaminated water. However, its physical and photocatalytic properties, and the application in vivo have not been well-characterized.
  
  
  METHODS
  Transmission electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, ultraviolet-visible absorption spectrum and the removal rate of nitrogen oxides were therefore analyzed. The antibacterial performance under in vitro and in vivo conditions was evaluated.
  
  
  RESULTS
  The apparent quantum efficiency for visible light illuminated TiO2-Pt is relatively higher than several other titania photocatalysts. The killing effect achieved approximately 2 log reductions of pathogenic bacteria in vitro. Illumination of injected TiO2-Pt successfully ameliorated the subcutaneous infection in mice.
  
  
  CONCLUSIONS
  This is the first demonstration of in vivo antibacterial use of TiO2-Pt nanoparticles. When compared to nanoparticles of some other visible-light responsive photocatalysts, TiO2-Pt nanoparticles induced less adverse effects such as exacerbated platelet clearance and hepatic cytotoxicity in vivo.
  
  
  CONCLUSIONS
  These findings suggest that the TiO2-Pt may have potential application on the development of an antibacterial material in both in vitro and in vivo settings.
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan.
authors.forename: Yao-Hsuan
authors.initials: YH
authors.lastname: Tseng
authors.forename: Der-Shan
authors.initials: DS
authors.lastname: Sun
authors.forename: Wen-Shiang
authors.initials: WS
authors.lastname: Wu
authors.forename: Hao
authors.initials: H
authors.lastname: Chan
authors.forename: Ming-Syuan
authors.initials: MS
authors.lastname: Syue
authors.forename: Han-Chen
authors.initials: HC
authors.lastname: Ho
authors.forename: Hsin-Hou
authors.initials: HH
authors.lastname: Chang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D008297:Male; D051379:Mice; D055668:Photochemical Processes; D010984:Platinum / Q000737:chemistry / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000188:drug therapy*; D013211:Staphylococcus aureus / Q000254:growth & development*; D013290:Streptococcal Infections / Q000188:drug therapy*; D013297:Streptococcus pyogenes / Q000254:growth & development*; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D000900:Anti-Bacterial Agents; C009495:titanium dioxide; D010984:Platinum; D014025:Titanium