Study of the In Vitro Biodegradation Behavior of Mg–2.5Zn–xES Composite for Orthopedic Application

Abstract

Non-degradable steel and titanium implants used to replace defects of the locomotor system or fabricate vascular stents provide maximum stability but have too many drawbacks. However; the defects in oxide layer and the corrosive nature of physiological environment, the thermodynamic tendencies make the alloys susceptible to release of cationic species in the form of corrosion, which result in triggering various biological factors and compromises the mechanical integrity of the implanted materials. Currently, biodegradable magnesium alloys are considered as promising materials for creation of fixation devices in orthopedics and cardiovascular surgery. In this work, zinc (Zn) and eggshell (ES) reinforced biodegradable magnesium alloy (Mg–2.5Zn), and environment concise (eco) composite (Mg–2.5Zn–xES) was fabricated using disintegrated melt deposition (DMD) technique. In vitro experiments were conducted to explore the effect variable concentration of ES ( 3 and 7 wt%) on the biodegradation behavior of Mg–Zn alloy using simulated body fluid (SBF) at 37 ℃. The corrosion behavior of the Mg–2.5Zn–xES alloys was explored in SBF solution using different techniques such as weight loss measurement, hydrogen evolution, potentiodynamic polarization, electrochemical Impedance Spectroscopy (EIS). EIS revealed increased in vitro degradation of the biodegradable magnesium alloy, and ecofriendly composite as the percentage of ES reinforcement was increased. X-ray diffraction (XRD) was performed to observe the chemical composition of elements and reaction products present in the degraded samples after the corrosion process.