Translocation and neurotoxicity of iron oxide nanoparticles in the central nervous system

ENVR 80

Weiyue Feng, fengwy@mail.ihep.ac.cn, Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, 19 B, Yu Quan Road, Shi Jing Shan, Beijing, 100049, China
Iron nanomaterials are of considerable interest for application in nanotechnology-related fields. Therefore, the safety evaluation of iron nanoparticles in an organism is needed. The central nervous system (CNS) is a target organ either for medical application or for occupational exposure.

Studying the translocations, distributions and metabolism of Fe2O3 nanoparticles in CNS, we found that the intra-nasally instilled nanoparticles were rapidly transported into the brain and reached in the deep brain regions with a size selection manner. Though vacuolation of neuronal cells in the CA3 hippocampus has been observed in the early days of instillation, the damage could be self-repaired in the following days. However, the oxidative stress and the ultrastructural alteration in nerve cells could be observed after Fe2O3 nanoparticle low dose repeated intranasal exposure. Furthermore, the in vitro study in a human glioma cell line (U251) exhibited different cytotoxic behaviors between the alpha-Fe2O3, gamma-Fe2O3 and magnetic Fe3O4 nanoparticles. Our results demonstrated that physicochemical properties are important in their toxic effects in organism.