Quercetin-conjugated magnetic nanoparticles inhibit Staphylococcus aureus growth and biofilm formation via downregulation of Coa and Hla genes.

Abstract

The research investigated the effects of that magnetic nanoparticles coated with the plant-based flavonoid quercetin have on the growth of Staphylococcus aureus. The synthesis of magnetic nanoparticles proceeded through co-precipitation and further involved quercetin coating using a dextran stabilizer. A combined product of these materials received the chemical name Fe₃O₄@Dex-QT. The study included multiple analytical tests such as FTIR (Fourier Transform Infrared Spectroscopy), FE-SEM (Field Emission Scanning Electron Microscopy), EDS (Energy-Dispersive X-Ray Spectroscopy) and XRD (X-ray diffraction) together with cellular and molecular assays. Biofilm detection experiments showed that 95% of studied microorganisms had moderate-to-strong biofilm formation abilities. The examined strains that formed biofilms exhibited complete biofilm inhibition at a minimum concentration of 512 μg/mL. Post-treatment with Fe₃O₄@Dex-QT nanoparticles, the Coa and Hla genes were expressed at 30 and 20% levels respectively, as determined through RT-PCR analysis. The research uncovered that Fe₃O₄@Dex-QT nanoparticles demonstrate successful antibacterial properties against S. aureus strains, making them viable for substituting conventional antibiotics.