Fig. 4

Synergistic CDT/PTT in vitro. (a) Biocompatibility of FTRNPs at mild acidic conditions (pH = 6.0) and neutral conditions (pH = 7.4) without H₂O₂. (b) Synergistic CDT/PTT cytotoxicity of FTRNPs at mild acidic conditions (pH = 6.0) and neutral conditions (pH = 7.4) with H₂O₂ (50 µM). Cell viability (c) and Calcein-AM/PI staining (d) of 4T1 cells with different treatments (PBS/FTRNPs (100 µg/mL, Fe₃O₄), mild acidic conditions/ neutral conditions, with/without irradiation (808 nm, 1 W/cm², 5 min), with/without magnetic targeting) with H₂O₂ (50 µM). (e) FL images of 4T1 cells incubated with DCFH-DA probe under different conditions (PBS/FTRNPs (100 µg/mL, Fe₃O₄), mild acidic conditions/neutral conditions, with/without magnetic targeting). (f) Quantification of DCFH-DA probe after different treatments. (g) Flow cytometric apoptosis/necrosis analysis based on Annexin V-APC/PI staining assay of 4T1 cells with different treatments (PBS/FTRNPs (100 µg/mL, Fe₃O₄), mild acidic conditions/ neutral conditions, with/without irradiation (808 nm, 1 W/cm², 5 min), with/without magnetic targeting).