Mechanical In Vitro Corrosion And Bioactivity Properties Of Mg Sn Hydroxyapatite Biodegradable Orthopedic Composites

Abstract

Biodegradable metallic materials like Magnesium (Mg) have been considered as newlinepotential material for medical implant applications. Mg exhibits excellent biocompatibility, bioactivity and biodegradability properties with mechanical characteristics similar to that of natural bone. However, lower corrosion resistance in physiological conditions affects the mechanical integrity of Mg in orthopedic implants applications. Recent literature revealed the role of Tin (Sn) on improving the corrosion resistance of Mg.Hydroxyapatite (HA) is known to have high bioactivity and widely used in orthopedic and orthodontic fields. The present research work investigates the mechanical, corrosion and bioactivity properties of different compositions of Mg-Sn alloys and Mg-Sn/HA composites. The aim of the study is to develop Mg-Sn/HA composites using squeeze casting process while varying the concentrations of Sn (1wt% and 5wt%) and HA (5wt% and 10wt%). To improve the bonding between ceramic particles and Mg matrix in Mg-Sn/HA composites, newlineelectroless coating of the HA with Sn (Mg-Sn-HASn) is adopted in this research. newlineThe compression strength, corrosion resistance and in vitro bioactivity behavior of newlinethe Mg-Sn alloys, Mg-Sn/HA and Mg-Sn/HASn composites were evaluated by performing the compression test, Tafel and electrochemical impedance spectroscopy (EIS) technique and immersion tests respectively in simulated body fluid (SBF) environment. In-vitro bioactivity test was performed in SBF for 14 days of immersion period.Analysis of the results indicated that 5wt% of Sn and 5wt% of HA in Mg matrix newlineis the suitable composition for improved corrosion resistance, optimum strength, and newlinebioactivity. Furthermore, electroless Sn coated HA reinforced Mg composites showed remarkable improvement in terms of strength, in-vitro degradation and bioactivity as compared to the composites prepared with un-coated HA particles. newline newline newline newline newline newline