title: Fabrication and in vitro characterization of magnetic hydroxycarbonate apatite coatings with hierarchically porous structures.
abstract: Hydroxycarbonate apatite/Fe(3)O(4) composite coatings (MHACs) with hierarchically porous structures were fabricated by electrophoretic deposition of CaCO(3)/Fe(3)O(4) particles on Ti6Al4V substrates followed by treatment with phosphate buffer solution (PBS) at 37 degrees C. The effects of Fe(3)O(4) on the conversion rate of calcium carbonate to hydroxycarbonate apatite and the porous structures and in vitro bioactivity of MHACs were investigated. After soaking CaCO(3)/Fe(3)O(4) coatings in PBS, hydroxycarbonate apatite nucleates heterogeneously on the surfaces of CaCO(3)/Fe(3)O(4) particles and forms a plate-like structure. Fe(3)O(4) increases the velocity of nucleus formation of hydroxycarbonate apatite. After soaking for 1day, the percentage of unreacted calcium carbonate for MHACs is approximately 9.1%, lower than the approximately 41.0% for hydroxycarbonate apatite coatings (HCACs). As the CaCO(3)/Fe(3)O(4) coatings are converted to MHACs, macropores with a pore size of approximately 4mum on the coatings and mesopores with a pore size of approximately 3.9nm within the hydroxycarbonate apatite plates are formed. The mesopores remain in the MHACs after treatment with PBS for 9 days, while they disappear in the HCACs. Simulated body fluid immersion tests reveal that Fe(3)O(4) improves the in vitro bioactivity of biocoatings. The amount of bone-like apatite precipitated on the surfaces of MHACs is greater than that on the surfaces of HCACs.
authors: Institute for Advanced Ceramics, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, China.
authors: Yaping
authors: Y
authors: Guo
authors: Yu
authors: Y
authors: Zhou
authors: Dechang
authors: D
authors: Jia
authors: Qingchang
authors: Q
authors: Meng
mesh_terms: D000327:Adsorption; D001031:Apatites / Q000138:chemical synthesis* / Q000737:chemistry; D002254:Carbonates / Q000138:chemical synthesis* / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000737:chemistry; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D016062:Porosity; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites; D002254:Carbonates; D020099:Coated Materials, Biocompatible; C413465:hydroxycarbonate apatite