Fig. 8

SiNPs were internalized and activated ER stress in RAW264.7 cells. The cells were treated with 50 μg/ml SiNPs for 24 h. Representative images of SEM (a) and TEM (b) respectively indicated the visualization of particle aggregates on the cellular surface, and uptake in macrophage after SiNPs treatment. Scale bar = 200 nm, 1 or 2 μm. c The uptake of SiNPs was further measured by energy dispersive spectrometry. In coincidence with the TEM image, silicon (red) and oxygen (green) elements were detected. Scale bar = 3 μm. d Representative TEM images indicated ER stress as evidenced by ER expansion and degranulation (black arrow). Scale bar = 1 μm. e The expressions of ER stress indicators, Bip and CHOP were detected by Western blot and the densitometric analysis was performed. *p < 0.05 vs Control. Data are expressed as means ± SD of three independent experiments