Assessment of the surface properties and evaluation of toxicity of anodized pure Mg according to various stabilizers in electrolyte

Plasma oxidation of metallic Mg improves its corrosion resistance by controlling the biodegradation rate. Recently, sodium silicate (Na₂SiO₃) has been used as the stabilizer in an alkaline electrolyte for anodization. However, Na₂SiO₃ is formed of Si(OH)₄ in the solution, which is converted to SiO₂, and that could remain in the body as undegradable particles. Therefore, the aim of this study was to compare glycerol and Na₂SiO₃ as biocompatible stabilizers by cytotoxicity assessments and in ovo. The applied current value was decreased by adding glycerol, and it was insufficient to cause spark formation. Although the Mg ion volume in elution of the glycerol group was higher than that in the Na₂SiO₃ group, the growth of the chicken embryo and number of somites were higher with the glycerol than with the Na₂SiO₃ stabilizer. The oxide film formed due to the addition of Na₂SiO₃ contributed to improving the corrosion resistance, but it did not show a positive effect on biocompatibility from the perspective of cell viability and in ovo analysis.