Fig. 3

a) ROS generation efficiency of TPASe, BODIPY 493/503, and the commercial photosensitizers Ce6 and RB was assessed using the fluorescent probe DCFH-DA. b) Dynamics of continuous fusion of LDs stimulated with TPASe induction at STED laser power. Scale bar: 2 µm. c) Dynamics of continuous fusion of LDs stimulated with BODIPY 493/503 induction at same laser power of (b). Scale bar: 2 µm. d) Number and size statistics of LDs during their dynamic and continuous fusion under coincubation of TPASe with A549 cells. Data are mean ± SD (n = 8 areas from 8 cells). e) Number and size statistics of LDs during their dynamic and continuous fusion under coincubation of BODIPY 493/503 in A549 cells. Data are mean ± SD (n = 8 areas from 8 cells). f) STED imaging of RAW 264.7 cells induced by ox-LDL (0, 10, 20, 50, 80 µg mL−1) to form foam cells using TPASe. λex = 488 nm, λem = 650–725 nm, and λSTED = 775 nm. Scale bar: 5 µm. g) Protein level of CD36 under treatment with different concentrations of ox-LDL (0, 10, 20, 50, and 80 µg mL−1) was assessed via western blotting. h) STED imaging of RAW 264.7 cells induced by ox-LDL (50 µg mL−1) to form foam cells using TPASe at various times (0, 4, 8, 12, and 24 h). λex = 488 nm; λem = 650–725 nm. λSTED = 775 nm. Scale bar: 5 µm. i) Protein level of CD36 expression under time-course ox-LDL treatment (0, 4, 8, 12, and 24 h) was assessed via Western blotting. GAPDH was used as a loading control to standardize the loading amount. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. Statistical analysis was conducted on the data for three times. j) Schematic diagram of nonlinear fusion of lipid droplets and foam cell formation, the image created using Microsoft PowerPoint.