Spirulina-incorporated micro arc oxidation coating on magnesium alloy: A sustainable approach to enhance bioactivity and corrosion resistance

This study examines spirulina's incorporation into MAO coatings on a magnesium alloy (Mg-0.1Ag-0.15Ca0.2Ce-0.1Mn-0.1Sn-0.2Sr-0.5Zn) for biomedical use. SEM-EDS and XRD confirmed spirulina's successful integration into a MgO layer, revealing a granular structure and enhanced hydrophilicity, with the contact angle decreasing from 105.9 degrees to 25.3 degrees. Corrosion rate in SBF dropped significantly from 0.075 mm/year to 4.95 x 10-5 mm/year with spirulina. Bioactivity tests showed improved apatite formation with a Ca/P ratio of 1.66. These results suggest that spirulina-MAO coatings could enhance corrosion resistance, hydrophilicity, and bioactivity in magnesium-based implants.