title: The bactericidal efficacy of a photocatalytic TiO(2) particle mixture with oxidizer against Staphylococcus aureus.
abstract: By proving the bactericidal effects of a low-concentration titanium dioxide (TiO(2)) particle mixture against Staphylococcus aureus, we hope to ultimately apply a mixture of this type as part of a clinical treatment regimen. A bacterial suspension of S. aureus 1 x 10(5) CFU/ml was added dropwise to a TiO(2) particle mixture (19 ppm TiO(2)) and irradiated by ultraviolet (UV) light. The colony-forming units were counted and the bacterial survival rate was calculated. In the control sample, the bacterial survival rate was 83.3% even after 120 min. In the TiO(2) mixture + UV sample, the bacteria count dropped sharply, reaching 17.3% of the baseline value at 30 min and 0.4% at 60 min. TiO(2) particles dispersed in water mixtures are known to elicit highly efficient UV absorption and greater bonding to bacteria. A reaction of the TiO(2) with another oxidizer altered the aqueous pH and accelerated the photocatalytic chemical reaction. The TiO(2) particle mixture showed high antibacterial action against S. aureus even at a low concentration.
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Biomedical Science, Nagasaki University, Nagasaki 852-8501, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Asahara
authors.forename: Hironobu
authors.initials: H
authors.lastname: Koseki
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tsurumoto
authors.forename: Koutaro
authors.initials: K
authors.lastname: Shiraishi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shindo
authors.forename: Koumei
authors.initials: K
authors.lastname: Baba
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Taoda
authors.forename: Nao
authors.initials: N
authors.lastname: Terasaki
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial; D050296:Microbial Viability; D053758:Nanoparticles; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000528:radiation effects*; D014025:Titanium / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D000900:Anti-Bacterial Agents; C009495:titanium dioxide; D014025:Titanium