Chitosan/metal oxide nanocomposites: synthesis, characterization, and antibacterial activity.

With the growing concern of biofilm-associated infections and drug-resistant bacteria, an increasing interest in developing novel antibacterial agents is an urgent priority. Metal oxide-based polymeric materials are able to distinguish mammalian cells from bacterial cells and thus provide long-term antibacterial growth inhibition. Herein, we report the preparation of MgO, NiO and chitosan-coated metal oxide (CS–MO) nanocomposites via a simple in situ chemistry approach. Fourier transform infrared spectroscopy, X-ray diffraction patterns and X-ray photoelectron spectra results proved the formation of CS–MgO and CS–NiO nanocomposites. Also, the particle sizes were observed to be 18.3 and 25.5 nm for CS–NiO and CS–MgO, respectively. All the samples exhibited antibacterial activities against the Escherichia coli and Staphylococcus aureus strains; however, more effective against S. aureus compared to E. coli. Noticeably, 5 μg/mL CS–NiO comparatively exhibited highest bactericidal capability where E. coli and S. aureus viabilities were reduced to 25–47% after 12 h incubation. After treatment with 15 μg/mL of CS–NiO, ∼98% of S. aureus and 92.3% of E. coli cells were inhibited. [ABSTRACT FROM AUTHOR]