Multifaceted applications of chitosan-L-ornithine modified ZnO nanoparticles: Antibacterial, antioxidant, and anticancer potentials

Developing polymeric inorganic nanoparticle-based nanomedicines has significantly advanced antibacterial and anticancer treatments. These innovative agents have attracted significant attention due to their unique physicochemical properties and promising efficacy in targeting bacteria and cancer cells. The primary objective of this study is to investigate the synthesis of chitosan and L-ornithine-supported zinc oxide nanoparticles (ZnCsLO NPs) to assess their biological effects. The X-ray diffraction (XRD) pattern confirmed the synthesis of ZnO and ZnCsLO NPs, with wurtzite hexagonal structure. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) showed nano-flake and polygonal structures for ZnO and ZnCsLO NPs, respectively. Fourier transform infrared (FTIR) spectroscopy of ZnO and ZnCsLO NPs revealed characteristic peaks such as ZnO, chitosan, and L-ornithine molecules. The photoluminescence (PL) spectra of ZnO and ZnCsLO NPs displayed green emission peaks at 519 nm and 527 nm respectively, attributed to oxygen vacancies and inherent defects. The antibacterial activity was tested against various Gram-positive and Gram-negative bacterial strains using the well diffusion method. The ZnCsLO NPs exhibited higher antibacterial activity than ZnO NPs. In terms of anti-oxidant activity, ZnCsLO NPs exhibited the highest scavenging activity compared to ZnO NPs against DPPH. The anticancer activity of ZnO and ZnCsLO NPs was tested against the breast cancer cell line MDA-MB-231, where ZnCsLO NPs exhibited higher anticancer activity than ZnO NPs. Toxicity studies of ZnCsLO NPs on human fibroblast L929 showed less harmful effect on healthy cells compared to ZnO. Based on the findings of this research, there is a strong indication that ZnCsLO NPs hold great potential as a nanomaterial well-suited for advanced biomedical industrial applications.