Fig. 3

In vitro cytotoxicity and synergistic antitumor effects of PTT/SDT. A Infrared thermal images of the CHINPs at different concentrations under 808 nm NIR laser irradiation (2.0 W cm⁻², 10 min). B Photothermal temperature–time curves of the CHINPs at different CHINPs concentrations and C different power densities of 808 nm NIR laser. D Photothermal temperature–time curves of an CHINPs aqueous solution for six cycles at a power intensity of 2.0 W cm⁻² under irradiation by 808 nm NIR laser. E The ROS production of CHINPs after different time of US irradiation was detected by SOSG. F Relative cell viability of 4T1 cells after coincubation with various concentrations of CHINPs for 3 h, 6 h,12 h and 24 h. G ROS production in 4T1 cells after different treatments was observed by DCFH-DA staining and CLSM. Scale bar: 50 μm. H Flow cytometry of ROS production in 4T1 cells as stained with DCFH-DA after different treatments. I CLSM images of 4T1 cells costained with PI (red fluorescence) and calcein-AM (green fluorescence) after different treatments, Scale bar: 50 μm. J Flow cytometry apoptosis assay of 4T1 cells after the incubation with CHINPs under different treatments followed by staining with Annexin-FITC and PI