Novel magnetic nanocomposites combining selenium and iron oxide with excellent anti-biofilm properties

In this work, a novel magnetic nanocomposite combining selenium nanoparticles (SeNPs) with iron oxide nanoparticles (IONPs) was synthesized for the first time, in which the size of the iron oxide nanoparticles was 7-12 nm, and nearly spherical or rod-like selenium nanoparticles were obtained according to the different pH values of the reaction mixtures. Selenium incorporation into iron oxide nanoparticles was improved by using a chitosan coating with pentasodium triphosphate as a crosslinking agent. The micromorphology, crystalline structure and magnetic properties of the nanocomposites were characterized by a transmission electron microscope, X-ray diffractometer and a superconducting quantum interference device. More importantly, the nanocomposites exhibited excellent anti-biofilm activity in the presence of an external magnetic field with significantly less toxicity toward human dermal fibroblast cells. The relative fraction of dead-to-live bacteria of the nanocomposites (400.0%) was much higher than that of SeNPs (51.6%) and IONPs (60.0%) by using ImageJ analysis. In this manner, the results of this study suggest that this presently created composite of selenium nanoparticles and iron oxide nanoparticles should be further studied (including in vivo assessment for blood compatibility and immune response) for a wide range of magnetically controlled biomedical applications.