Fabrication and properties of a biodegradable β-TCP/Zn-Mg bio-composite

Abstract

The good biocompatibility and moderate degradation rate of Zn-based alloys have attracted increasing attention in biodegradable biomaterials field. However, the unsatisfactory mechanical properties of pure zinc limited its biomedical applications. In this study, Zn-1Mg alloy and 1vol%β-TCP/Zn-1Mg composite were fabricated using stirring casting assisted by ultrasonic vibration. Microstructure, mechanical properties, corrosion behavior and osteotoxicity of Zn-1Mg alloy and 1vol%β-TCP/Zn-1Mg composite were tested and /evaluated. In comparison with the matrix alloy, the addition of 1vol%β-TCP refined the grain size. The yield strength(YS), ultimate tensile strength(UTS) and elongation of the as-extruded composite were 249.3 MPa, 330.1 MPa, and 11.7% respectively, which increased by 10.2%, 9.9%, and 101.7% respectively. The corrosion rate of 1vol%β-TCP/Zn-1Mg composite in SBF is 46 μm/a. Corrosion resistance of the composites was improved after ultrasonic treatment. The proliferation rate of MC3T3-E1 cell for Zn-1Mg alloy and 1vol%β-TCP/Zn-1Mg composite extracts were above 80% after 1-5days in culture. As the culture time increased, the 1vol%β-TCP/Zn-1Mg composite showed superior cytocompatibility compare to Zn-1Mg alloy.