Fig. 4

Ferroptosis therapeutic mechanism evaluated on tumor cells. a, CLSM images of 4T1 cells treated with PBS (control), MSPION3, SFN1@MSPION3, BQR1@MSPION3, or SFN/BQR1@MSPION3, and stained with DCFH-DA, showing intracellular ROS generation. b, c, ROS fluorescence distributions (b) and quantified ROS fluorescence intensities (c) of the 4T1 cells after various treatments evaluated by flow cytometry. d, e, The relative intracellular GSH level (d), and GPX4 level (e) in 4T1 cells after treatment with PBS (control), MSPION3, SFN1@MSPION3, BQR1@MSPION3, or SFN/BQR1@MSPION3. f, Schematic illustration of the underlying mechanism of the intracellular redox balance disrupted by SFN/BQR1@MSPION3. The SFN/BQR1@MSPION3 facilitates the Fenton reaction, attenuates GPX4 activity, and blocks the DHODH system, synergistically potentiating LPO accumulation and cancer cell ferroptosis