A novel water-soluble polymer nanocomposite containing ultra-small Fe3O4 nanoparticles with strong antibacterial and antibiofilm activity

A novel water-soluble polymer nanocomposite containing ultra-small iron oxide nanoparticles, intercalated into a biocompatible matrix of 1-vinyl-1,2,4-triazole and N-vinylpyrrolidone copolymer has been synthesized for the first time. The use of an original polymer matrix ensured effective stabilization of the crystalline phase of iron oxides at an early stage of its formation in an ultra-small (2–8 nm, average diameter is 4.8 nm) nanosized state due to its effective interaction with the functional groups of copolymer macromolecules. At the same time, the copolymer ensures the long-term stability of iron oxide nanoparticles in a nanosized dispersion. The structure and physicochemical properties of the copolymer and nanocomposite were studied by elemental analysis, 1H and 13C NMR spectroscopy, gel permeation chromatography, Fourier-transform infrared spectroscopy, transmission and scanning electron microscopy, dynamic light scattering, thermogravimetric analysis and differential scanning calorimetry. The nanocomposite exhibits high antibacterial and antibiofilm activity against both Gram-negative and Gram-positive bacteria. The nanocomposite at a concentration of 500 and 1000 μg mL−1 leads to complete death of Escherichia coli cells after 24 and 3 hours of incubation, respectively. The nanocomposite at a concentration of 100 μg mL−1 leads to complete death of Staphylococcus aureus cells after 24 hours of incubation. Which indicates the potential of using the nanocomposite for the treatment of superficial wounds and purulent-inflammatory complications.