In vitro biodegradation, electrochemical corrosion evaluations and mechanical properties of an Mg/HA/TiO2 nanocomposite for biomedical applications

Abstract

In this study, a biodegradable Mg/HA/TiO2 nanocomposite was prepared using a milling-pressing-sintering powder metallurgy technique. The combined effects of hydroxyapatite (HA) and titania (TiO2) on the corrosion behavior of pure Mg were investigated via in vitro immersion and electrochemical tests in a simulated body fluid (SBF), and changes in the mechanical properties were analyzed using a compression test. Furthermore, X-ray diffraction, Fourier-transform infrared spectroscopy, atomic-force microscopy, field-emission scanning electron microscopy and transmission electron microscopy were used to investigate the composition and microstructure of the Mg/HA/TiO2 bionanocomposite as well as the morphology of the corrosion products. The corrosion rate of the Mg/HA nanocomposite decreased both in terms of mass loss and hydrogen evolution with a decrease in HA from 27.5 to 5 wt% and an addition of 15 wt% TiO2. By sintering the Mg/HA/TiO2 nanocomposites, MgTiO3 nanoflakes were formed with a hierarchical microstructure on the surface of the samples. The compression and electrochemical tests indicated that the ternary Mg/12.5HA/10TiO2 nanocomposite had a good combination of mechanical properties and corrosion resistance of 12.17 kΩ cm2 in the SBF solution. The cell culture results indicated that the Mg/HA/TiO2 nanocomposite was biocompatible with osteoblasts.