Synergistic nano-therapeutics: Ag-doping unlocks superior antifungal, antioxidant, and selective cytotoxicity in magnesium ferrite spinels

This investigation details the synthesis, characterization, and multifaceted biomedical applications of pure magnesium ferrite (MFO) and novel silver-doped magnesium ferrite (MSFO) nanoparticles via a facile co-precipitation method. Leveraging the chemical stability and magnetic properties of spinel ferrites, strategic silver incorporation was employed to amplify therapeutic potential. XRD, FTIR, UV-Vis-NIR, and SEM confirmed the successful formation of crystalline nanoparticles, showing that silver doping significantly refined particle size, modified morphology, and dramatically reduced the optical band gap from 2.56 eV to 1.73 eV, enhancing physicochemical properties. The biomedical efficacy evaluation revealed that MSFO, while active against E. coli , demonstrated superior antifungal action against Aspergillus niger , remarkably outperforming the commercial control. MSFO also exhibited enhanced antioxidant capabilities compared to MFO. The most significant finding is their remarkable selective cytotoxicity: MSFO displayed significantly improved dose-dependent toxicity against A549 lung cancer cells while exhibiting substantially lower toxicity to normal L929 fibroblast cells, indicating a high selective index for cancer targeting. The intracellular ROS levels in MSFO-treated cancer cells were about six times higher than those in the control. This selectivity, coupled with confirmed apoptosis induction in cancer cells, positions silver-doped magnesium ferrite nanoparticles as highly promising, biocompatible candidates for targeted cancer therapeutics and paves the way for advanced nanomaterials with synergistic properties.