Shahrouz Zamani Khalajabadi
Universiti Teknologi, Malaysia
Title: Fabrication, bio-corrosion behavior and biocompatibility of a Mg/HA/TiO2 nanocomposite for biomedical applications
Biography
Biography: Shahrouz Zamani Khalajabadi
Abstract
Recently, magnesium/hydroxyapatite (Mg/HA) composites have shown the potential to serve as biodegradable metal matrix composite implants that can repair load-bearing defects in osseous tissue. However, the mechanical properties and corrosion resistance of magnesium-hydroxyapatite composites have been restricted by the significant agglomeration of HA particulates. In this study, the bio-corrosion properties of a Mg/HA-based composite were improved by the addition of different amounts of hydroxyapatite and TiO2 nanopowders to pure magnesium and fabrication of the Mg/HA/TiO2/MgTiO3 nanocomposites using a blend-cold press-sinter powder metallurgy technique. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, atomic force microscopy and field-emission scanning electron microscopy were used to characterize the compositions of the corrosion products and the surface morphologies of the corroded specimens. Based on the electrochemical test, the corrosion resistance of the nanocomposites is shown to increase from 0.25 kΩ cm2 to 12.17 kΩ cm2 with the addition of 10 wt% TiO2; however, the ultimate compressive strength decreased from ~237 to ~184 MPa. During sintering process, synthesis of the MgTiO3 nanoflakes via the mechanically induced self-propagating reaction on the Mg-12.5HA-10TiO2 and Mg-5HA-15TiO2 (wt%) pellets decreased the contact area between the physiological solution and the substrate; as a result, the corrosion rate decreased compared to that of the Mg-27.5HA and Mg-20HA-5TiO2 nanocomposites. The corrosion products formed on the nanocomposites surface are shown to be primarily Mg(OH)2, HA, Ca3(PO4)2 and amorphous calcium-phosphate compounds. After 9 days of cell culture, the cell viability decreased by increasing of TiO2 amount; however, the Mg/HA/TiO2 nanocomposites remained biocompatible with osteoblast cells.