Selenium nanoparticles for the prevention of PVC-related medical infections

It has been shown that selenium elicits antibacterial properties. It is not known, however, if reducing elemental selenium to the nanoscale further enhances these properties. The purpose of this study was to investigate the antibacterial properties of selenium nanoparticles on polyvinyl chloride (PVC), a medical tube substrate prone to bacterial adhesion and biofilm formation. Through the reduction of selenium salts by glutathione, selenium nanoparticles were precipitated onto PVC samples. Characterization by scanning electron microscopy, energy dispersive spectroscopy, transmission electron spectroscopy, and dynamic light scattering indicated the presence of elemental selenium having particle size diameters that averaged 100nm. Selenium nanoparticle-coated PVC and uncoated PVC samples were seeded with Staphylococcus aureus and cultured for 24h. Crystal violet staining and optical density readings were used to evaluate bacterial growth, while intracellular thiol assays were used to determine the method of bactericide. Results indicated that selenium nanoparticles significantly inhibited the growth of Staphylococcus aureus after 24h as compared to uncoated PVC by means of intracellular thiol depletion. These findings demonstrated the potential of selenium nanoparticles as a novel antibacterial coating for PVC and, thus, should be further investigated for improving the efficacy numerous PVC-related medical devices.