Fig. 5
ICG/PTX@RGE-EV contributes to apoptosis of U251 cells. A Cell viability following chemotherapy detected by CCK8 assay (x-axis represents PTX concentration, which was set to 0–6.4 µg/mL). B Cell viability following hyperthermia detected by CCK8 assay (x-axis represents ICG concentration, which was set to 0–6.4 µg/mL). C Cell viability following chemotherapy-hyperthermia detected by CCK8 assay (x-axis represents PTX concentration, which was set to 0–6.4 µg/mL). U251 cells were incubated with PBS, RGE-EV, or PTX@RGE-EV for 48 h, respectively, or incubated with ICG@RGE-EV or ICG/PTX@RGE-EV for 4 h and then irradiated with 808 nm laser light (0.8 W/cm2) for five min, followed by incubation for 44 h. Each group was calculated by PTX concentration (0.2 µg/mL) in panel D–F. D Cell apoptosis identified by Calcein AM/PI staining assay following chemotherapy. E Cell apoptosis identified by Calcein AM/PI staining assay following hyperthermia. F Cell apoptosis identified by Calcein AM/PI staining assay following chemotherapy-hyperthermia. G Cell apoptosis rates determined by flow cytometry. Each group was calculated by PTX concentration (0.2 µg/mL). H Protein bands of Cleaved Caspase-3, Bax and Bcl-2 detected by Western blot analysis. I Relative protein expression of Cleaved Caspase-3, Bax and Bcl-2 detected by Western blot analysis. Measurement data were expressed as mean ± standard deviation. Data comparison was analyzed by one-way ANOVA among multiple groups, followed by Tukey’s post hoc test. *p < 0.05. The experiment was repeated three times independently