Fig. 4

In vitro cell targeting ability of TMVP1-ICG-NPs. (A) Confocal fluorescence images of cells treated with TMVP1-ICG-NPs, ICG-NPs, and free ICG (ICG concentration = 100 ng/mL) after 3 h of incubation (scale bar, 20 μm). The fluorescence images of 4’,6-diamidino-2-phenylindole (DAPI) and ICG were obtained at excitation wavelengths of 405 and 633 nm. 4T1 and MS751 cells overexpressing VEGFR-3 were generated via a lentiviral vector, and called 4T1-Flt-4 and MS751-Flt-4 cells, respectively. (B) TMVP1-ICG-NPs, ICG-NPs, and free ICG uptake by 4T1-Flt-4 and MS751-Flt-4 cells were detected by flow cytometry after 3 h of incubation. (C-D) The mean fluorescence intensity of 4T1-Flt-4 and MS751-Flt-4 cells treated with TMVP1-ICG-NPs, ICG-NPs, and free ICG (ICG concentration = 100 ng/mL) at 0.5 h, 1 h, 2 h, and 3 h detected by flow cytometry. Values of p < 0.05 were considered significant (ns: no significance, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001)