University of Kashan Journal of Nanostructures 2251-7871 16 4 2026 10 01 Green Selenium Nanocomposite Loaded with Ampicillin: Synthesis, Characterization, and Synergistic Antibacterial Activity Against Isolates from Prostate Cancer Patients 4717 4727 115633 10.22052/JNS.2026.04.021 EN Malik Ahmed A. Al-Yassari Department of Biology, College of Science, University of Kerbala, Iraq Kaisar Abdul Sajjad Hussein Department of Biology, College of Science, University of Kerbala, Iraq Journal Article 2026 05 02 This study aimed to prepare green selenium nanoparticles (SeNPs) using ashwagandha root extract, then load them with the antibiotic ampicillin (Amp-SeNPs) to improve its pharmaceutical properties and evaluate its synergistic inhibitory activity against resistant bacterial strains isolated from prostate cancer patients with urinary tract infections. Characterization techniques (FTIR, AFM, SEM) confirmed the success of the green synthesis, showing spherical nanoparticles with an average size of 106 nm before loading, which increased to 118 nm after loading, along with significant increases in surface roughness and root mean square height, confirming antibiotic conjugation. The study included three bacterial isolates: E. coli, K. pneumoniae, and P. aeruginosa. The inhibitory activity evaluation showed that the loaded nanocomposite (Amp-SeNPs) exhibited significant differences (P≤0.05) compared to the antibiotic or nanoparticles alone. The inhibition zone diameter against E. coli was 24.63±1.36 mm, compared to 1.25±0.366 mm for ampicillin alone and 11.88±1.74 mm for SeNPs alone. At the higher concentration, inhibition reached 27.50–27.75 mm for all three species, along with a marked reduction in MIC values. https://jns.kashanu.ac.ir/article_115633_5ed687de14d90e5a0b9ac75e2b4cf0c1.pdf