Dextran-coated superparamagnetic iron oxide nanoparticles activate the MAPK pathway in human primary monocyte cells

摘要

With the increase in applications of superparamagnetic iron oxide nanoparticles (SPIONs) in biomedicine, it is essential to investigate the bio-security of these nanoparticles, especially with respect to the human immune system. In the present study, the biological effects of dextran-coated superparamagnetic iron oxide nanoparticles (Dex-SPIONs) on human primary monocyte cells were evaluated. The results of the present study demonstrated that Dex-SPIONs can be identified in phagosomes or freed in the cytoplasm and did not affect cell viability or induce apoptosis. Notably, there were certain bulky vacuoles and a number of pseudopodia from the cell membrane, suggesting potential activation of human monocyte cells. In addition, the expression levels of pro-inflammatory cytokines interleukin (IL)-1 beta and tumor necrosis factor (TNF)-alpha were also increased following treatment with Dex-SPIONs. Simultaneously, the phosphorylation levels of mitogcn-activated protein kinase (MAPK) p38, c-Jun N-terminal kinase 1 and extracellular signal regulated kinase were markedly enhanced following nanoparticle exposure and MAPK inhibitors could abate the production of IL-1 beta and TNF-alpha. The results of the present study demonstrated that Dex-SPIONs could activate human monocyte cells and that activation of MAPK pathway may be involved in these effects.