Mineral substituted hydroxyapatite coatings deposited on nanoporous TiO2 modulate the directional growth and activity of osteoblastic cells†

Abstract

The biocompatibility of anodized titanium (TiO2) was improved by electrophoretically deposited mineral (strontium (Sr), magnesium (Mg) and zinc (Zn)) substituted hydroxyapatite (M-HAP). The M-HAP layer was grown on the anodized Ti surface at different deposition temperatures (room temperature, 60 and 80 C). The phases and morphologies of the M-HAP layers were influenced by the deposition temperature. The coatings were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy equipped with energy dispersive X-ray analysis (SEM-EDX). Also, the effects of temperature and the mineral substitution of Sr, Mg and Zn for Ca on the physiochemical and biological properties of the M-HAP coatings were evaluated by the mechanical strength, ion dissolution and proliferation, alkaline phosphatase (ALP) activity and osteogenic expression of osteoblast like cells MG66 (HOS). Thus, the M-HAP deposition of TiO2 will serve as a potential candidate for orthopedic applications.