Fig. 4
In vitro study. The relative cell viability of Fe2O3 and FP with or without US (1.0 MHz, 1.0 W m−2, 30 s) under a normoxic and b hypoxic conditions (***p < 0.001, **p < 0.01 and *p < 0.05). c The fluorescence ROS images and d quantitative analysis by flow cytometer of 4T1 cells staining with DCFH-DA and treated by FP NPs under different conditions. Scale bar: 40 μm. e The fluorescence images of 4T1 cells staining with calcein AM (green, live cells) & PI (red, dead cells) and RDPP and treated by FP NPs under the different conditions. Scale bar: 40 μm. f The flow cytometer apoptosis assay of 4T1 cells staining with PI and Annexin-FTIC