Fig. 3

N-GQDs induced iron overload, lipid peroxidation and inflammation in BV2 cells at a dose-dependent manner. a The cell viability of BV2 cells; b, c representative PE fluorescence histogram plots of BV2 cells showed necrotic cells using PI dye, and the quantitative results of necrotic percentages; d representative fluorescent images of intracellular ferrous iron level in BV2 cells showed orange using FerroOrange dye. The nucleus showed blue using DAPI. Scale bar: 20 µm; e, f representative FITC fluorescence histogram plot of BV2 cells showed cytosolic ROS production using DCFH-DA dye, and the quantitative results of mean fluorescence intensity (MFI); g, h representative FITC fluorescence histogram plot of BV2 cells showed lipid ROS using C11BODIPY581/591 dye, and quantitative results of mean fluorescence intensity (MFI); i, j, k the GSH/GSSG ratio, NADP+/NADPH ratio and MDA content in BV2 cells; l the expressions of ferroptosis biomarker proteins SLC7A11, GPX4 and ACSL4 in BV2 cells using western blotting analysis; m, n the levels of IL-1ß, TNF-α and IL-6 in BV2 cells. BV2 cells were treated with 25, 50 and 100 μg/mL N-GQDs for 24 h (n = 3). Data are showed as mean ± SD of three independent experiments. The one-way ANOVA followed by the Dunnett’s t test were used to determine statistical significance (*P < 0.05, **P < 0.01, ***P < 0.001 vs. the control)