Histological Evaluation of the Fetus Lung in NMRI Mice after Exposure to Iron Oxide Nanoparticles: an in vitro Study

Background and Aim: Iron oxide nanoparticles are used in fields related to nanotechnology including ecology, magnetic storage, imaging and medicinal purposes. Iron nanoparticles produce reactive oxygen species (Ros). These materials are able to cross the placenta. The aim of this study was to investigate toxic effect of iron oxide nanoparticles on fetal lung in mice. Methods: In this study, at day 14 of pregnancy, fetal lungs were removed and transferred to the Cell culture medium. The lungs were divided into 5 groups, including control, sham and experimental groups of 1, 2 and 3 (received respectively 10, 30 and 50 mg/kg nano iron oxide) and then they were incubated for 24 hours. For histopathological evaluation, lung tissues were stained with Hematoxylin-Eosin and the results were evaluated. Results: Mean number of bronchioles and the diameter of blood vessels in exprimental groups showed no significant difference compared with control and sham groups. Mean number of blood vessels in experimental groups 1 and 2 showed no significant difference compared to control and sham groups, while in the experimental group 3, mean number of blood vessels showed significant decrease compared to sham and control groups (p<0.05). Histopathological examination of lung after exposure to iron oxide nanoparticles showed signs of cytotoxicity including vacuole degeneration and necrosis. Conclusion: The finding of this study showed that in in vitro, conditions, iron oxide nanoparticles reduce number of blood vessels and have cytotoxic effects such as vacuole degeneration and necrosis in the lung tissue of the fetus, in a dose- dependent way.These results can be grounds for in vivo studies.