Cellular interactions of functionalized superparamagnetic iron oxide nanoparticles on oligodendrocytes without detrimental side effects: Cell death induction, oxidative stress and inflammation

International audience; Iron oxide nanoparticles have the capability to cross Blood Brain Barrier (BBB) and hence are widely investigated for biomedical operations in the central nervous system. Before being used in humans, it is necessary to investigate their biocompatibility, dosimetry and biological interaction. In the present study, in-house synthesized superparamagnetic iron oxide nanoparticles (SPIONs) were functionalized using the polymer, PolyEthylene Glycol and a fluorophore (Rhodamine) (fSPIONs). The interaction of fSPIONs with murine oligodendrocytes 158N revealed that the nanoparticles were taken up by the cells via endocytosis, and there was a dose-dependent increase in the intracellular iron content as revealed by flow cytometry, transmission electron microscopy and confocal microscopy. Nanoparticles remained stable inside the cells even after 24 h. In addition, interaction and/or accumulation of nanoparticles was supported by the possibility to isolate treated cells even after 24 h. Cell sorting capacity using a magnet depended on the amount of particles. Noteworthy, whereas these nanoparticles can interact per cell. fSPIONs exhibited good biocompatibility as no toxicological response, including morphological changes, loss of viability, oxidative stress or inflammatory response (IL-1β, IL-6 secretion) was observed. These data show that the in-house synthesized fSPIONs have no accumulate on 158N oligodendrocytes without the side effects on 158N cells, and constitute interesting tools for biomedical applications on nerve cells, including cellular imaging and targeting (oxidative stress, inflammation and cell death) that could be detrimental when a subsequent use of these nanoparticles in humans is considered.