title: Micropatterned TiO₂ nanotube surfaces for site-selective nucleation of hydroxyapatite from simulated body fluid.
abstract: TiO₂ nanotube layers can provide greatly enhanced kinetics for hydroxyapatite formation from simulated body fluid compared with smooth, compact TiO₂ surfaces. In the present work we show how this contrast in reactivity can be used to create highly defined lateral microstructures where bone-like hydroxyapatite can be deposited with very high selectivity. For this we used a photolithographic approach to produce micropatterned TiO₂ nanotube layers surrounded by compact oxide that were then immersed in a simulated body fluid (SBF) solution. Not only the tubular vs. flat geometry but also the finding that compact oxides created in phosphate electrolytes in particular suppress apatite deposition are crucial for a very high reactivity contrast. Overall the results show the feasibility of stimulating hydroxyapatite deposition at surface locations where needed or desired. This provides a valuable tool for biomedical device design.
authors.affiliation: Department of Materials Science, University of Erlangen-Nuremberg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Pittrof
authors.forename: Sebastian
authors.initials: S
authors.lastname: Bauer
authors.forename: Patrik
authors.initials: P
authors.lastname: Schmuki
mesh_terms: D001826:Body Fluids / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D010710:Phosphates / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D013431:Sulfates / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*
chemical_list: D004573:Electrolytes; D010710:Phosphates; D013431:Sulfates; C009495:titanium dioxide; D017886:Durapatite; D014025:Titanium