Figure 1

Exposure to iron oxide nanoparticles (IONPs) did not cause cytotoxicity to primary microglial cells. Primary microglial cells (4 × 10⁵ cells/mL) were either left untreated (naïve; NA), or pretreated with IONPs (1–50 μg Fe/mL) for 30 min followed by stimulation with LPS (100 ng/mL) for 24 h. (A) The nuclei of cells pretreated with IONPs and stimulated with LPS were visualized by confocal microscopy with Hoechst (blue) staining. In the bright field, cells treated with IONPs show numerous dark brown dots accumulated intracellularly. (B) The cell viability was determined by the MTT assay. Data are expressed as the mean ± SE of triplicate cultures. Results are a representative of three independent experiments.