Abstract
Green synthesis of nanoparticles (NPs) has gained significant attention due to its environmentally friendly approach and potential biomedical applications. This study focuses on the synthesis of selenium nanoparticles (SeNPs) and iron-selenium bimetallic nanoparticles (Fe-SeNPs) using Azadirachta indica leaf extract as a natural reducing and stabilizing agent. The synthesized nanoparticles were characterized using UV-Vis spectroscopy, DLS, FTIR, XRD, SEM, TEM, and TGA, confirming their successful synthesis. The therapeutic efficacy of SeNPs and Fe-SeNPs was evaluated against MCF-7 human breast cancer cells through MTT, wound healing, apoptosis, and yolk sac membrane (YSM) assays. Fe-SeNPs demonstrated greater cytotoxicity than SeNPs, with IC50 values of $50~\mu $ g/mL at 24 h and $30~\mu $ g/mL at 48 h. Both types of nanoparticles significantly inhibited cell migration (56.6% for SeNPs and 61.4% for Fe-SeNPs at 48 h) and promoted apoptosis, as confirmed by Annexin V/PI staining. Further, a dose-dependent inhibition of angiogenesis was observed in the YSM assay, with complete inhibition at higher concentrations. These results highlight the potential of green-synthesized SeNPs and Fe-SeNPs as promising candidates for breast cancer treatment by inducing cytotoxicity, suppressing migration and angiogenesis, and promoting apoptosis, thereby contributing to the advancement of nanoparticle-based cancer therapeutics.