Fig. 4.

Synergistic PTT/CDT antitumor effect of LET-11-Fe in vitro. Cell viabilities of 4T1 cells incubated with different concentrations of (A) LET-11 or (B) LET-11-Fe with or without 808-nm laser irradiation (0, 0.3, and 0.5 W cm⁻²; n = 5). (C) Cell viability of 4T1 cells with different treatments under laser irradiation (808 nm, 0.5 W cm⁻²; n = 5). *P < 0.05 and ****P < 0.0001, analyzed by 2-sided Student’s t test. (D) HPF-stained fluorescence images of 4T1 cells with different treatments. Scale bars, 20 μm. The irradiation density was 0.3 W cm^–2 at 808 nm, and the irradiation time was 10 min. (E) Flow cytometry analysis of 4T1 cells apoptosis induced by different treatments under laser irradiation (808 nm, 0.3 W cm⁻² for 10 min). FITC, fluorescein isothiocyanate.