Effect of nanostructured MgO directly grown on pure magnesium substrate on its in vitro corrosion and bioactivity behaviour
Majid Shahsanaei, Masoud Atapour, M. Shamanian, Nastaran Farahbakhsh, Swathi Naidu Vakamulla Raghu, Torsten Kowald, Sybille Krauß, Seyedsina Hejazi, Shiva Mohajernia, Manuela S. Killian
Abstract
This study introduces a nanostructured MgO coating fabricated via anodization in a non-aqueous electrolyte, offering a novel approach to addressing the challenges of corrosion resistance and biofunctionality. The surface was characterized before and after immersion testing using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests demonstrated a 2-fold reduction in the corrosion resistance compared to untreated magnesium. Biomineralization studies demonstrated the uniform formation of apatite with a Ca/P ratio of 1.35 on the nanostructured surface after 14 days in simulated body fluid (SBF), surpassing that of microstructured MgO. Hydrogen evolution decreased from 912±38 µL cm -2 for untreated Mg to 615±32 µL cm -2 for the Mg/MgO nanostructure and 545±29 µL cm -2 for the Mg/MgO/HA sample. These findings highlight the potential of nanostructured MgO coatings to advance Mg-based implants by providing enhanced corrosion protection, improved biomineralization, reduced hemolysis and increased cell viability, and reduced H 2 generation.