A novel method has been developed to rapidly deposit bone-like apatite with the assistance of ultraviolet （UV） light irradiation on the nanostructured titania in the simulated body fluid （SBF）. The process has three main steps： Ti-24Nb-4Zr-7.9Sn alloy was heated at 650℃ for 3 h, UV-light illumination in air for 4 h and soaking in the SBF for 3 d. A titania coating consisted of main rutile formed on the thermal oxidized Ti-24Nb-4Zr- 7.9Sn alloy. The UV not only converted the futile surface from hydrophilic to hydrophobic but also stimulated high surface activity. After 4 h UV illumination, the contents of Ti3＋ and hydroxyl groups on the oxidized sample were increased, while that of lattice O decreased. After 3 d of soaking in the SBF, a compact and uniform layer of carbonated hydroxyapatite （CHA） particles was formed on the UV-illuminated rutile surface whereas there was a few of HA to be viewed on the surface of as-oxidized Ti-24Nb-4Zr-7.9Sn alloy. Our study demonstrates a simple, fast and cost-effective technique for growing bone-like apatite on titanium alloys.
The mechanical properties and corrosion resistance of magnesium alloy composites were improved bythe addition of MgO surface modified tricalcium phosphate ceramic nanoparticles (m-β-TCP). Mg-3Zn-0.8Zr composites with unmodified (MZZT) and modified (MZZMT) nanoparticles were produced byhigh shear mixing technology. Effects of MgO m-β-TCP nanoparticles on the microstructure, mechanicalproperties, electrochemical corrosion properties and cytocompatibility of Mg-Zn-Zr/β-TCP compositeswere investigated. After hot extrusion deformation and dynamic recrystallization, the grain size ofMZZMT was the half size of MZZT and the distribution of m-β-TCP particles in the matrix was moreuniform than β-TCP particles. The yield tensile strength (YTS), ultimate tensile strength (UTS), andcorrosion potential (Ecorr) of MZZMT were higher than MZZT;the corrosion current density (Icorr) ofMZZMT was lower than MZZT. Cell proliferation of co-cultured MZZMT and MZZT composite sampleswere roughly the same and the cell number at each time point is higher for MZZMT than for MZZTsamples.
