Figure 3.

In vitro photodynamic and photothermal killing of cancer cells. (A) Detection of the lethality of nanomaterials at different concentrations against 4T1 cells. Different concentrations of ICG, PHSA-ICG, and PHSA-ICG-TAT were applied to 4T1 cells, and the activity of the cells was tested using the CCK-8 assay after irradiation with light at a wavelength of 808 nm for 5 min. **P<0.01, *P<0.05, compared with the control group; ^##P<0.01, comparison between PHSA-ICG and PHSA-ICG-TAT. (B) The photothermal and photodynamic capabilities of PHSA-ICG-TAT and ICG. The ICG and PHSA-ICG-TAT were irradiated with light at a wavelength of 808 nm for 5 min under the conditions of normal temperature, 4°C, and NaN₃. Subsequently, the activity of 4T1 cells was tested with the CCK-8 assay. **P<0.01, compared with the control group; ^##P<0.01, ^#P<0.05, comparison between ICG and PHSA-ICG-TAT. (C) The flow cytogram of the apoptosis of 4T1 cells after excitation of ICG, PHSA-ICG, and PHSA-ICG-TAT by light at a wavelength of 808 nm. (D) Statistics of transfer rate. **P<0.01, compared with the control group; ^##P<0.01, comparison between PHSA-ICG and PHSA-ICG-TAT. (E) Comet images of DNA damage to 4T1 cells after stimulation of ICG, PHSA-ICG, and PHSA-ICG-TAT. (F) Statistics of Tail DNA% in comet experiments. **P<0.01, compared with the control group; ^##P<0.01, comparison between PHSA-ICG and PHSA-ICG-TAT.

Abbreviations: CCK-8, Cell Counting Kit-8; ICG, indocyanine green; PHSA, PEGylated human serum albumin.