Improving the corrosion resistance and the osteointegration of hydroxyapatite coatings through the incorporation of synthesized mesoporous SiO2/HA particles

In the present article, mesoporous SiO 2 /hydroxyapatite (HA) composite particles were produced via employing CTAB as a template, and then co-electrodeposited on Nitinol biomedical alloy with HA. Characterization results showed the formation of about 200 nm spheres with numerous plate-like particles and slit-shaped pores. The composite coatings were applied by using different concentrations of particles in the deposition electrolyte (500, 750, 1000, and 1250 mg/L). Morphological observations revealed that with an increase in particle concentration, the film exhibited greater compactness, leading to the formation of particle agglomerates in certain regions. This was further proved by the atomic force microscopy analysis where the porosity of the layers decreased, and the roughness diminished by raising particle concentration. This made composite coatings a little more hydrophobic than pure HA coating . Furthermore, the incorporation of these particles significantly enhanced the corrosion protection of the composite coatings. Specifically, the corrosion current density for the sample coated with a solution containing 1000 mg/L of particles decreased to nearly one-fifth of that observed in the pure HA coating. Last but not least, MG-63 osteoblasts were provided with a convenient environment on composite coatings since they fed on Si nutritious element to reproduce and proliferate more aggressively than on pure HA layer.