Background: Due to their biological and physiochemical characteristics, metal-based nanoparticles show promise as antimicrobials and therapeutic agents. Aim: This study aimed to biosynthesize AuNPs from A. baumannii broth and test their antibacterial and ant-virulence properties. Materials and methods: UV-vis, FTIR, XRD, TEM, FESEM and AMF were used to analyze biosynthesized gold nanoparticles. The well method diffusion assay was utilized to determine Ab-AuNPs' antibacterial activity against five bacterial strains. Microtiter plate was used to study the effect of Ab-AuNPs on biofilm formation in five bacterial isolates.

Background: Gold nanoparticles (AuNPs), unlike chemotherapy, may destroy cancer cells without harming normal cells. Objective: For the first time, Acinetobacter (A.) baumannii-biosynthesized AuNPs (Ab-AuNPs) were evaluated for anticancer properties. Materials and methods:The Ab-AuNPs were characterized by UV-visible spectroscopy, TEM, FE-SEM, AFM, XRD analysis, and FTIR. The MTT assay was used to determine the antiproliferative efficacy of the Ab-AuNPs at different concentrations against prostate cancer (PC3) and human breast normal cell line (MCF-10). Potential apoptoticmediated cell death was investigated using acridine orange and propidium iodide staining and mitochondrial membrane potential (MMP). Results: Biosynthesized Ab-AuNP had a zeta potential below 30 mV at -22 mV, suggesting particles stability with no aggregation. The average size was estimated at 66 nm (range 20-90 nm). Ab-AuNPs inhibited PC3 cell proliferation dose-dependently, with no adverse effect on MCF-10 cells. The mean lethal dose (IC50) was 13.72 µg/mL, and the maximal inhibitory concentration was 25.50 mg/mL (57.33% and 80.67%, respectively). Examining PC3 cancer cells treated with Ab-AuNPs at IC50 for 24 hours by flow cytometry revealed an increase in apoptosis that resulted in the disruption of the membrane and vacuoles of the lysosomes, which corresponded with the depletion of MMP. This was in contrast to MCF-10 AuNPs-treated cells, which showed no adverse effects. Conclusions: Producing gold nanoparticles in an A. baumannii broth culture is simple, inexpensive, and non-toxic to healthy cells. They showed anticancer effects by inducing apoptosis, making them a potential effective anticancer agent.