Surface Effect of Iron Oxide Nanoparticles on the Suppression of Oxidative Burst in Cells

Overproduction of reactive oxygen species (ROS) is an unwanted phenomenon, leading to cellular damages. The aim of this study was to investigate the ability of neat and surface-modified iron oxide nanoparticles (IONs) to eliminate ROS produced by immune cells. The employed coating included heparin (ION@Hep) or heparin and chitosan grafted with phenolic compounds famous for antioxidant properties, i.e., gallic acid (ION@Ch-G) or phloroglucinol (ION@CH-P). A total peroxyl radical-trapping potential assay showed that both types of the phenolic compounds-modified IONs exhibited superior radical scavenging activity over the neat and ION@Hep particles at 100 μg/mL. Up to ~ 75 μg/mL, the particles were non-toxic towards RAW 264.7 macrophages. Capability of the particles to limit ROS production was investigated in vitro on polymorphonuclear (PMN) cells isolated from human whole blood and expressed as an ability to reduce the oxidative burst in the stimulated cells, as well as a potential to increase the viability of bacteria cultivated with the PMN cells. The highest viability of bacteria was observed for the neat and ION@Ch-G, while the ION@Ch-G particles also the most effectively inhibited the oxidative burst. The results indicated that ROS scavenging depend on the presence of polymer and selection of phenols, enriching the IONs.