Nystatin-mediated bismuth oxide nano-drug synthesis using gamma rays for increasing the antimicrobial and antibiofilm activities against some pathogenic bacteria and<i>Candida</i>species

The novelty of the present research is the synthesis of bismuth oxide nanoparticles (Bi₂O₃ NPs) loaded with the antifungal nystatin drug <i>via</i> gamma rays for increased synergistic antimicrobial potential against some pathogenic bacteria and <i>Candida</i> species. The full characterization of the synthesized Bi₂O₃ NPs-Nystatin was achieved by XRD, FT-IR, HR-TEM, and SEM/EDX mapping techniques in order to analyze the crystallinity, chemical functional groups, average particle size, morphology, and elemental structure, respectively. The antimicrobial activities of Bi₂O₃ NPs-Nystatin were examined against pathogenic bacteria and <i>Candida</i> species, including the zone of inhibition (ZOI), minimum inhibitory concentration (MIC), and antibiofilm activity. Additionally, the SEM/EDX method was performed to investigate the mode of action on the treated <i>Candida</i> cells. Our results revealed that Bi₂O₃ NPs-Nystatin possessed a well-crystallized semi-spherical shape with an average particle size of 27.97 nm. EDX elemental study of the synthesized Bi₂O₃ NPs-Nystatin indicated a high level of purity. Interestingly, the synthesized Bi₂O₃ NPs-Nystatin displayed encouraging antibacterial behavior against almost all the tested bacteria and a synergistic antifungal potential toward the investigated <i>Candida</i> species. Additionally, Bi₂O₃ NPs-Nystatin was found to be a promising antibiofilm agent, resulting in inhibition percentages of 94.15% and 84.85% against <i>C. albicans</i> (1) and <i>E. coli</i>, respectively. The present research provides a revolutionary nano-drug-based solution to address the increasing global resistance of pathogenic microbes at low concentrations, thus offering a new infectious disease treatment technique that is cost effective, eco-friendly, and works in an acceptable time frame.