Relationship of grain size to the physicochemical properties and osteogenesis in magnesium–zinc–calcium alloys for bone implants

Abstract

Magnesium–zinc–calcium alloy has emerged as a key focus in the field of medical degradable materials due to its excellent biodegradability and osteoconductive properties. Grain size is crucial for the physicochemical and biological properties of Mg–Zn–Ca alloy, but it has not been clearly elucidated yet. In this research, Mg-1Zn-0.2Ca-1.0MgO with different grain sizes were prepared to investigate the effect of grain size on the physicochemical properties, corrosion resistance, and osteogenesis. The results indicate that grain refinement improves the mechanical properties and enhances the corrosion resistance of the alloy. The bone surface area to bone volume ratio, bone surface area to tissue volume ratio, and bone volume fraction of the 0.6–0.8 μm group show significantly better performance compared to the 2–3 μm group and 5–6 μm group, indicating that grain refinement can promote the osseointegration between alloy and natural bone. This may be achieved by enhancing the metabolic intensity of alanine, aspartate, glutamate, serine, and glycine around the implant. This work illustrates the effect of grain size on the osseointegration of bone implants and provides a reference for optimizing the properties of bone implant alloys.