An innovative strategy for bioactivation of β-Ti12Mo6Zr2Fe alloy surface by dip-coating method with potential application in the biomedical field

Abstract

Titanium alloys, particularly the β-Ti12Mo6Zr2Fe (TMZF), have received significant attention in orthopedic applications due to their mechanical properties and biocompatibility. However, the poor osteointegration of Ti alloys has limited their orthopedic applications, but it can be improved by adding a bioactive layer. In the present study, the dip-coating method was used to build layer-by-layer a bioactive coating on the TMZF substrate surface. It consisted of three layers: phosphate-functionalized TMZF surface with TEP solution in an acidic medium, anchored 58S5Sr particles dispersed in TEOS, and a deposit of a protective TEP layer in an acidic medium. For this purpose, different surface treatments were previously performed on the substrate before the deposition of the bioactive layer: sanding and laser texturing. The 58S bioactive glass with 5 % CaO substituted by SrO was synthesized by the sol-gel method and fully characterized. The coated samples were characterized by scanning electron microscopy and XPS spectroscopy. The laser textured sample with greater laser beam scans showed a uniform and adherent bioactive coating, resulting from changes in the morphology and chemical composition of the substrate surface. In addition, the presence of bioactive coating provides an excellent bioactive response after immersion in SBF solution at 37 °C showing apatite-related deposits on the samples’ surface after 24 h of immersion. A model of the physical and chemical anchorage of the 58S5Sr bioactive glass coating on TMZF was proposed.