Green synthesis of Fe-doped manganese oxide nanoparticles: enhanced their antibacterial and anticancer properties assessed by biological analysis

Eco-friendly synthesis methods are becoming increasingly important as a sustainable way to produce nanoparticles, thereby improving their potential for biomedical applications. The nanoparticles have a small size, a high surface area-to-volume ratio, and the ability to be functionalized with targeting ligands, making them ideal for drug delivery, imaging, and diagnostic purposes. In anticancer therapies, nanoparticles can enhance treatment efficacy by improving drug solubility, enabling controlled release, and selectively targeting cancer cells, thereby minimizing side effects on healthy cells. In the present work, the green engineering of manganese oxide (GEMn₂O₃) and iron-doped manganese oxide (GEFe@Mn₂O₃) nanoparticles (NPs) was achieved using a green process with Cynoglossum zeylanicum extract. The synthesized nanoparticles were characterized by XRD, FTIR, DLS, PL, and FESEM analysis. The antibacterial activity of GEMn₂O₃ and GEFe@Mn₂O₃ NPs was tested against S. aureus. GEFe@Mn₂O₃NPs showed significant antibacterial activity as compared to the GEMn₂O₃NPs. The antioxidant activity of GEMn₂O₃ and GEFe@Mn₂O₃ NPs was studied again using the DPPH assay. Cytotoxicity assays demonstrated that GEMn₂O₃ and GEFe@Mn₂O₃ NPs exhibit significant anticancer activity against a human blood cancer cell line (MOLT-4). The findings indicate a strong correlation between the increased oxygen vacancies of the GEFe@Mn₂O₃ NPs and their enhanced biocidal properties. This suggests that GEFe@Mn₂O₃ nanoparticles (NPs) are promising candidates for antibacterial and anticancer applications due to their unique physicochemical properties, including enhanced redox activity, reactive oxygen species (ROS) generation, and potential for targeted cellular interaction. The incorporation of iron (Fe) and manganese oxide (Mn₂O₃) provides synergistic effects that can disrupt microbial cell membranes and induce apoptosis in cancer cells through oxidative stress. Moreover, the engineered nanostructure of GEFe@Mn₂O₃ NPs may offer improved biocompatibility and the ability to penetrate biological barriers, making them suitable for therapeutic delivery and biomedical interventions.