title: Optimization of amino group density on surfaces of titanium dioxide nanoparticles covalently bonded to a silicone substrate for antibacterial and cell adhesion activities.
abstract: A composite consisting of titanium dioxide (TiO2) particle, the surface of which was modified with amino groups, and a silicone substrate through covalent bonding at their interface was developed, and antibacterial and cell adhesion activities of the composite were evaluated. The density of the amino groups on the TiO2 particle surface was controlled by the reaction time of the modification reaction. The degradation rate of CH3CHO in the presence of the TiO2 particles under UV irradiation decreased with an increase in the amino group density on the TiO2 surface. On the other hand, the number of L929 cells adhering on the TiO2/silicone composite increased with an increase in the amino group density. From the above two results, the optimum density of amino groups for both photoreactivity and cell adhesiveness was estimated to be 2.0-4.0 molecules/nm2. The optimum amino group-modified TiO2/silicone composite sheet (amino group density, 3.0 molecules/nm2) showed an effective antibacterial activity for Escherichia coli bacteria under UV irradiation.
authors.affiliation: Department of Bioengineering, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Okada
authors.forename: Shoji
authors.initials: S
authors.lastname: Yasuda
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kimura
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Iwasaki
authors.forename: Seishiro
authors.initials: S
authors.lastname: Ito
authors.forename: Akio
authors.initials: A
authors.lastname: Kishida
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Furuzono
mesh_terms: D000079:Acetaldehyde / Q000378:metabolism; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D001673:Biodegradation, Environmental; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D004926:Escherichia coli / Q000187:drug effects; D008422:Materials Testing; D051379:Mice; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures; D010777:Photochemistry; D012828:Silicones; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D012828:Silicones; C009495:titanium dioxide; D014025:Titanium; D000079:Acetaldehyde