eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2025-03-31 18 1 909 919 10.13005/bpj/3139 64872 article Zinah Ayyed Habeeb 1 Sanaa Khudhur Jameel 1 Mais Emad Ahmed 2 Medical Microbiology Department, College of medicine, AL-Iraqia University, Baghdad, Iraq. Department of Biology, College of Science, University of Baghdad, Jadriya, Baghdad, Iraq Studies on the functional characteristics of Se nanoparticles (SeNP) have become increasingly popular in recent decades because of their strong selectivity, stability, and high biocompatibility. Numerous studies demonstrate SeNP's anticarcinogenic properties. In order to defeat bacteria that are resistant to antibiotics, new strategies need to be developed. A subclass of antimicrobial peptides known as selenium nanoparticles (NPs) can be used either in place of or in addition to well-known antibiotics. SeNPs have been investigated with the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), zeta potential, and transmission electron microscopy (TEM)., and UV-visible analysis. The antibacterial qualities of SeNPs were confirmed by the generated nanoparticles showed increased antimicrobial activity at different concertation (1000-64) µg/ml In the good diffusion assay, the NPs efficiently suppressed the growth of susceptible SeNPs have zones of inhibition between 5-19 mm against Gram-Negative while against Gram Positive bacteria Staphylococcus epidermidis and Staphylococcus aureus bacteria have zones of inhibition between 6-17 mm , respectively. Our study has shown that combining various antimicrobials with different mechanisms of action led to an extensive variety of inhibition and raised efficacy, particularly against germs that are resistant to several medications. The best anti- human breast cancer cell line MCF7 properties of nanocomposite against the above cell lines was in the case of MCF7 cell line. According to the above findings, the SeNPs may be administrated for the treatment of several types of human breast cancer in humans. Ovarian cancer had increased nanoparticle sensitivity. At a concentration of 25 μL/mL, SeNPs demonstrated excellent cytotoxicity and anticancer activity, making them suitable for use as an anticancer agent.The physicochemical characteristics, experimental setup, and concentrations of SeNPs exploited in this study must all be carefully stated. https://biomedpharmajournal.org/vol18no1/synthesis-characterization-and-cytotoxic-evaluation-of-selenium-nanoparticles/ Ascorbic Acid Selenium Nanoparticles X-ray Diffraction Cell lines (MCF7) GI50 value