In vitro characterization of self-assembled nanoflowers structures on Mg ZX10 for biomedical application

Abstract

Magnesium (Mg) alloys are promising candidates for biodegradable implants; however, their rapid degradation in physiological environments limits their clinical application. This study investigates the effect of nanoflower-like (NF) inorganic coatings on the corrosion resistance and hemocompatibility of a Mg-0.94Zn-0.15Ca alloy (Mg ZX10). Coatings were formed by immersing sterilized samples in simulated body fluid (SBF) or phosphate buffer (PB) under cell culture conditions (37 °C, 5% CO2, 95% humidity) for 3 or 7 days. The surfaces of sterilized (control) and NF-coated Mg ZX10 alloys were characterized using scanning electron microscopy (SEM), Raman spectroscopy, Fourier-transform infrared attenuated total reflectance (FTIR-ATR), X-ray photoelectron spectroscopy (XPS) and electrochemical testing, and hemolysis assays. Immersion in both media induced the formation of NF-like aggregates that completely covered the Mg ZX10 surfaces. These coatings exhibited hierarchical structures with morphology dependent on immersion conditions. FTIR and XPS confirmed magnesium carbonate hydroxide hydrates in SBF-treated samples and phosphate compounds in PB-treated samples. Electrochemical evaluation in Hank’s balanced salt solution demonstrated decreased corrosion resistance in NF-coated Mg ZX10 due to porous coatings that failed to act as effective corrosion barriers, resulting in increased degradation relative to sterilized controls. Nonetheless, NF coatings improved hemocompatibility without significantly compromising corrosion protection. These findings suggest that simple immersion-based techniques can generate nanostructured coatings that enhance the biomedical performance of Mg alloys, supporting their potential application in biodegradable implant technology.