New Mg-Ca-Zn Amorphous Alloys: Biocompatibility, Wettability and Mechanical Properties

Abstract Mg-Ca-Zn alloys are considered to be biodegradable materials and nontoxic to the living cell. Thus, they are promising candidates for use in orthopedic applications. In the present work, two new Mg-based glassy alloys (Mg72Ca12Zn16 and Mg63Ca15Zn22) are synthesized by melt spinning. The prospect of these alloys for biomedical application is assessed by evaluating and comparing their mechanical properties, biodegradation and biocompatibility with the well established glassy alloy composition, Mg60Ca5Zn35, synthesized under identical conditions. With decreasing Zn content in the composition, the density of the melt spun alloys decreases. The new alloys show lower hardness and an about ~35% lower Young's modulus than the Mg60Ca5Zn35 alloy. In vitro degradation behavior in Hank's balanced salt solution (HBSS) solution yields a higher degradation rate for the new alloys than for the existing Mg60Ca5Zn35 alloy. Degradation products are characterized using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), confirming the presence of magnesium hydroxide (Mg(OH)2), hydroxyapatite (HAp), and ternary calcium magnesium zinc (Ca2Mg6Zn3) phases. In vitro biocompatibility studies with a mouse osteoblast cell line (MC3T3-E1) clearly demonstrates the non-cytotoxic nature of the alloys. The results altogether suggest possible biomedical applications of the new Mg-based glassy alloys.