Biomedical subjects

Xiaobing Zhao

Publications and source records attributed to Xiaobing Zhao.

2 recordsLinked to original sources

PubMed2005

Acid-induced bioactive titania surface.

Nano- and conventional-TiO(2) powders were deposited onto titanium alloy using atmospheric plasma spraying technology. As-sprayed titania coatings were treated by H(2)SO(4) and HCl solutions at room temperature for 24 h, and the bioactivity was evaluated by simulated body fluid tests. Measured X-ray diffraction patterns indicated that as-sprayed titania coatings obtained from both nano and conventional powders were composed of primary rutile as well as a small quantity of anatase and Ti(3)O(5). The surface of as-sprayed coatings prepared from the conventional powder was rougher than that from nanopowder. After immersion in simulated body fluid for 2 weeks, both acid-treated nano- and titania coatings have induced carbonate-containing hydroxyapatite to form on the surfaces. However, this phenomenon did not appear on the surface of as-sprayed nano- and conventional-titania coatings. The results obtained indicated that the bioactivity of plasma sprayed titania coatings was improved by the acid treatment and had nothing to do with phase composition and particle size of the original TiO(2) powders.

Coated Materials, Biocompatible↗

PubMed2005

Plasma-treated nanostructured TiO(2) surface supporting biomimetic growth of apatite.

Although some types of TiO(2) powders and gel-derived films can exhibit bioactivity, plasma-sprayed TiO(2) coatings are always bioinert, thereby hampering wider applications in bone implants. We have successfully produced a bioactive nanostructured TiO(2) surface with grain size smaller than 50 nm using nanoparticle plasma spraying followed by hydrogen plasma immersion ion implantation (PIII). The hydrogen PIII nano-TiO(2) coating can induce bone-like apatite formation on its surface after immersion in a simulated body fluid. In contrast, apatite cannot form on either the as-sprayed TiO(2) surfaces (both <50 nm grain size and >50 nm grain size) or hydrogen-implanted TiO(2) with grain size larger than 50 nm. Hence, both a hydrogenated surface that gives rise to negatively charged functional groups on the surface and small grain size (<50 nm) that enhances surface adsorption are crucial to the growth of apatite. Introduction of surface bioactivity to plasma-sprayed TiO(2) coatings, which are generally recognized to have excellent biocompatibility and corrosion resistance as well as high bonding to titanium alloys, makes them more superior than many current biomedical coatings.

Apatites↗