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

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 for the biomedical purpose, it is necessary to investigate its biocompatibility, dosimetry and biological interaction. In the present study, in-house synthesized superparamagnetic iron oxide nanoparticles (SPIONs) were functionalized using the polymer, PolyEthylene Glycol (PEG) and a fluorophore (Rhodamine). The interaction of these nanoparticles with murine oligodendrocytes 158N was studied using different assays. 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 cells even after 24 h. Cell sorting capacity using a magnet depended on the number of particles interact per cell. SPIONs exhibited good biocompatibility as no toxicological responses, including morphological changes, loss of viability, oxidative stress or inflammatory response (IL-1β, IL-6 secretion) were observed. Together, these data show that the in-house synthesized SPIONs have no side effects on 158N cells, and constitute interesting tools for biomedical applications across brain, including cellular imaging and targeting.