Enhanced Mechanical Properties, Corrosion Resistance, Cytocompatibility, Osteogenesis, and Antibacterial Performance of Biodegradable Mg–2Zn–0.5Ca–0.5Sr/Zr Alloys for Bone‐Implant Application

Abstract

Magnesium (Mg) alloys have been widely used in bone fixation, bone repair, and cardiovascular stents as biodegradable bone‐implant materials. However, their clinical application is limited due to their fast corrosion rate and poor mechanical stability. Here we report the development of Mg‐2Zn‐0.5Ca‐0.5Sr (MZCS) and Mg‐2Zn‐0.5Ca‐0.5Zr (MZCZ) alloys with improved mechanical properties, corrosion resistance, cytocompatibility, osteogenesis performance, and antibacterial capability for biodegradable bone‐implant applications. The hot‐extruded (HE) MZCZ sample exhibited the highest ultimate tensile strength of 255.8±2.4 MPa and the highest yield strength of 208.4±2.8 MPa among all alloy samples and an elongation of 15.7±0.5% due to the recrystallization and grain‐refining effect of Zr. The HE MZCS sample showed the highest corrosion resistance among all samples, with the lowest corrosion current density of 0.2±0.1 μA/cm2 and lowest corrosion rate of 4±2 μm/y obtained from electrochemical testing, and a degradation rate of 368 μm/y and hydrogen (H2) evolution rate of 0.83±0.03 mL/cm2/d obtained from immersion testing for 21 d in Hanks’ solution. The MZCZ sample showed the highest cell viability in relation to MC3T3‐E1 cells among all alloy extracts, indicating good cytocompatibility except at 25% concentration. Furthermore, the MZCZ alloy showed good antibacterial capability against S. aureus.This article is protected by copyright. All rights reserved