Recubrimientos de hidroxiapatita biológica dopada con magnesio y reforzada con TiO₂: Síntesis y caracterización

Bio-coatings of TiO₂ and biological hydroxyapatite (HA) doped with magnesium (TiO₂/HA-Mg) were deposited on AISI 316L stainless steel by dip-coating technique, from suspensions of HA-Mg powders (which were obtained by hydrothermal treatment of bovine bone in solutions of Mg(NO3)2) in TiO₂ sols. Biological hydroxyapatite powders doped with Mg were characterized by XRD and FT-IR analytical techniques, in order to evaluate the compositional changes. On the other hand, the coating's characteristics were evaluated by scanning electron and optic microscopies, adhesion force to the substrate, in vitro bioactivity in SBF and corrosion resistance. The bovine bone hydrothermally treated allowed to obtain hydroxyapatite with greater reactivity due to its doping with Mg, what was confirmed throughout the electrochemical characterization of the films. The modification of HA with Mg does not significantly affect the physical and mechanical properties of the TiO ₂/HA films. An increment in the bioactivity of the HA was only observed when it was modified with 10% Mg, so that during the immersion of this coating in SBF shows an initial stage of biomaterial dissolution and the subsequent stage of apatites formation on its surface.