Surface Defect Engineering on CeO ₂ Nanoparticles Through Green Process Using Vitex trifolia Leaf Extract and Their Structural, Optical, and Biomedical Application

Background Nanotechnology based research offers a favorable method to address breast cancer and bacterial resistance, two serious global health challenges. Breast cancer is one of the most commonly diagnosed tumors global and is an important cause of death among women. Purpose This study presents the synthesis of cerium dioxide nanoparticles (CeO 2 NPs) using Vitex trifolia leaf extract in an eco-friendly approach. This process results in the CeO 2 NPs becoming biocompatible. This approach addresses environmental concerns by utilizing safe, non-toxic chemicals and reducing preparation costs, making the NPs suitable for healthcare applications. Materials and Methods Characterization techniques, including XRD, FTIR, DLS, UV-Vis, FESEM, EDAX, PL, and antimicrobial as well as anti-cancer analysis, were employed. Results XRD patterns revealed a cubic structure for the CeO 2 NPs, while morphological observations showed agglomerated uniform nano-belt-like structures with uniform grain boundaries. The agar well diffusion technique demonstrated the antimicrobial activities of CeO 2 NPs against human pathogens, suggesting their potential as nano-antibiotics. In vitro tests on MDA-MB-231 cells found that the synthesized CeO 2 NPs had minimal toxicity. However, they did show potential to be cytotoxic, resulting in increased lethality against the cancer cells. The AO/EtBr dual staining method was employed to assess cell viability, confirming that CeO 2 nanoparticles induced apoptotic cell death in MDA-MB-231 cells. Conclusion These findings proved that CeO 2 NPs inhibit cell growth and cause apoptosis in breast cancer cells and are employed as a tool for individualized therapy for targeting and eliminating breast cancer cells.