Physicochemical properties and in vitro cytocompatibility of modified titanium surfaces prepared via micro-arc oxidation with different calcium concentrations

Abstract

ObjectiveTo explore the effect of calcium concentration in the electrolyte solution on the physicochemical properties and biocompatibility of coatings formed by micro-arc oxidation (MAO) on titanium surfaces. MethodsThe surfaces of pure titanium plates were modified by MAO in an electrolytic solution containing calcium acetate (CA; C4H6CaO4) at concentrations of 0.05, 0.1, 0.2, or 0.3M and β-glycerophosphate disodium salt pentahydrate (β-GP; C3H7Na2O6P·5H2O) at a fixed concentration of 0.02M. Surface topography, elemental characteristics, phase composition, and roughness were investigated by scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, and a surface roughness tester, respectively. To assess the cytocompatibility and osteoinductivity of the surfaces, MC3T3-E1 preosteoblasts were cultured on the surfaces in vitro, and cell morphology, adhesion, proliferation, and differentiation were observed. ResultsThe porous MAO coating was composed primarily of TiO2 rutile and anatase. The amount of TiO2 rutile, the Ca/P ratio, and the surface roughness of the MAO coating increased with increasing CA concentration in the electrolyte solution. Ca3(PO4)2, CaCO3, and CaTiO3 were formed on MAO-treated surfaces prepared with CA concentrations of 0.2 and 0.3M. Cell proliferation and differentiation increased with increasing CA concentration, with MC3T3-E1 cells exhibiting favorable morphologies for bone–implant integration. ConclusionsMAO coating improves the surface characteristics and cytocompatibility of titanium for osseointegration. Higher CA concentration in the MAO electrolyte solution has a positive effect on the surface properties, chemical composition, and cell response.