Biocorrosion and Cytotoxicity Studies on Biodegradable Mg-Based Multicomponent Alloys

Magnesium-based multicomponent alloys with different compositions, namely Mg₆₀Al₂₀Zn₅Cu₁₀Mn₅ (Mg60 alloy), Mg₇₀Al₁₅Zn₅Cu₅Mn₅ (Mg70 alloy), and Mg₈₀Al₅Cu₅Mn₅Zn₅ (Mg 80) alloys, were prepared using the disintegrated melt deposition technique. The DMD technique is a distinctive method that merges the benefits from gravity die casting and spray forming. This approach facilitates high solidification rates, process yields, and reduced metal wastage, resulting in materials with a fine microstructure and minimal porosity. Their potential as biodegradable materials was assessed through corrosion in different simulated body fluids (SBFs), microstructure, and cytotoxicity tests. It was observed that the Mg60 alloy exhibited low corrosion rates (~× 10^-5 mm/year) in all SBF solutions, with a minor amount of corrosive products, and cracks were observed. This can be attributed to the formation of the Mg₃₂(AlZn)₄₉ phase and to its stability due to Mg(OH)₂ film, leading to excellent corrosion resistance when compared to the Mg70 and M80 alloys. Conversely, the Mg80 alloy exhibited high corrosion rates, along with more surface degradation and cracks, due to active intermetallic phases, such as Al₆Mn, Al₂CuMg, and Al₂Cu phases. The order of corrosion resistance for the Mg alloy was found to be ASS > HBSS > ABP > PBS. Further, in vitro cytotoxicity studies were carried out using MDA-MB-231 tumor cells. By comparing all three alloys, in terms of proliferation and vitality, the Mg80 alloy emerged as a promising material for implants, with potential antitumor activity.