In this study, composite films of stearic acid–modified magnesium oxide whiskers (Sa–w-MgO)/poly-l-lactic acid (PLLA) were prepared through solution casting, and the in vitro degradation properties and cytocompatibility of the composites with different whisker contents were investigated. The results showed that the degradation behavior of the composite samples depended significantly on the whisker content, and the degradation rate increased with the addition of MgO content. Furthermore, the degradation of the composites with higher contents of whiskers was influenced more severely by the hydrophilicity and pH value, leading to more final weight loss, but the decomposition rate decreased gradually. Furthermore, the pH value of the phosphate buffer solution (PBS) was obviously regulated by the dissolution of MgO whiskers through neutralization of the acidic product of PLLA degradation. The cytocompatibility of the composites also increased remarkably, as determined from the cell viability results, and was higher than that of PLLA at the chosen whisker content. This was beneficial for the cell affinity of the material, as it notably led to an enhanced biocompatibility of the PLLA, in favor of promoting cell proliferation, which significantly improved its bioactivity, as well.

An in situ Mg-Al hydrotalcite (LDH) film was prepared using a one-step hydrothermal method on the surface of a medical magnesium alloy. The importance and influence of the reaction parameters on the corrosion resistance of the LDH coatings were optimized and investigated through an orthogonal array and range analysis. The reaction parameters included the temperature, reaction time, pH, and concentration of the aluminum source. The relationship between the parameters and corrosion resistance performance of each coating was compared with the chemical composition, electrochemical corrosion current, and hydrogen evolution rate. Suitable reaction parameters were obtained. The morphology, element distribution, adhesion strength, and electrochemical properties of the preferred coatings were further analyzed and evaluated to optimize the treatment process. The results showed that temperature had the most significant impact on the quality of the LDH coating; a suitably high temperature, a longer reaction time, a higher aluminum source concentration, and a high pH were conducive to forming high-quality LDH coatings. There was an inverse relationship between the corrosion resistance and the LDH-to-Mg(OH)₂ content ratio of the coatings. The optimal reaction parameters for this Mg-Al LDH coating on the substrate were 130 °C for 8 h at a pH of 13 using a 10 mM Al³⁺ solution.