Cytotoxicity studies of Fe₃O₄ nanoparticles in chicken macrophage cells

Magnetic Fe₃O₄ nanoparticles (Fe₃O₄-NPs) have been widely investigated for their biomedical applications. The main purpose of this study was to evaluate the cytotoxic effects of different sizes of Fe₃O₄-NPs in chicken macrophage cells (HD11). Experimental groups based on three sizes of Fe₃O₄-NPs (60, 120 and 250 nm) were created, and the Fe₃O₄-NPs were added to the cells at different doses according to the experimental group. The cell activity, oxidative index (malondialdehyde (MDA), superoxide dismutase (SOD) and reactive oxygen species (ROS)), apoptosis and pro-inflammatory cytokine secretion level were detected to analyse the cytotoxic effects of Fe₃O₄-NPs of different sizes in HD11 cells. The results revealed that the cell viability of the 60 nm Fe₃O₄-NPs group was lower than those of the 120 and 250 nm groups when the same concentration of Fe₃O₄-NPs was added. No significant difference in MDA was observed among the three Fe₃O₄-NP groups. The SOD level and ROS production of the 60 nm group were significantly greater than those of the 120 and 250 nm groups. Furthermore, the highest levels of apoptosis and pro-inflammatory cytokine secretion were caused by the 60 nm Fe₃O₄-NPs. In conclusion, the smaller Fe₃O₄-NPs produced stronger cytotoxicity in chicken macrophage cells, and the cytotoxic effects may be related to the oxidative stress and apoptosis induced by increased ROS production as well as the increased expression of pro-inflammatory cytokines.