Corrosion Resistance and Biocompatibility of Calcium Phosphate Coatings with a Micro-Nanofibrous Porous Structure on Biodegradable Magnesium Alloys.

Magnesium (Mg) and its alloys have exhibited great potential for orthopedic applications; however, their poor corrosion resistance and potential cytotoxicity have hindered their further clinical applications. In this study, we prepared a calcium phosphate (Ca-P) coating with a micro-nanofibrous porous structure on the Mg alloy surface by a chemical conversion method. The morphology, composition, and corrosion performance of the coatings were investigated by scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), immersion tests, and electrochemical measurements. The effects of the preparation temperature of the Ca-P coatings were analyzed, and the results confirmed that the coating obtained at 60 °C had the densest structure and the best corrosion resistance. In addition, a systematic investigation into cell viability, ALP activity, and cell morphology confirmed that the Ca-P coating had excellent biocompatibility, which could effectively promote the proliferation, differentiation, and adhesion of osteoblasts. Hence, the Ca-P coating demonstrates great potential in the field of biodegradable Mg-based orthopedic implant materials.

The microstructure, mechanical properties, corrosion performance and biocompatibility of hydroxyapatite reinforced ZK61 magnesium-matrix biological composite.

Magnesium (Mg)-based composites, as biomaterials, have attracted widespread attention due to their adjustable mechanical properties like elastic modulus, ductility, ultimate tensile strength, and corrosion resistance. In this study, hydroxyapatite (HA) reinforced ZK61 Mg-matrix composites were prepared by powder metallurgy and hot extrusion methods. The influence of the content of HA (10 wt%, 20 wt%, and 30 wt%) on the microstructure, density, mechanical properties, corrosion property and biocompatibility were investigated. The results showed that the density and yield strength of the composites match those of natural bone. Moreover, the composite with 10 % HA (ZK61-10HA) exhibited the best corrosion resistance, as determined by the electrochemical measurement and immersion test in simulated body fluid (SBF) at 37 °C. In addition, the ZK61-10HA composite significantly enhanced the cell viability (≥78 %) compared with ZK61 alloy in vitro testing. It is demonstrated that the mechanical properties, corrosion resistance and biocompatibility of Mg alloy can be effectively controlled by adjusting the content of HA, which suggested that the ZK61-HA composites were promising candidates for degradable implant materials.