Fig. 4

Fluorescence investigation on the distribution patterns of FEPT in 4T1 tumor-bearing Balb/c mice. A In vivo NIR-II fluorescence imaging of 4T1 tumor-bearing mice after intravenous injection of FEPT at 0.5, 2, 5, 8, 12, 24, and 48 h, respectively. Tumors are highlighted in dotted circles. B Fluorescence images of sacrificed major organs and tumors at 48 h post-injection (under 808 nm laser excitation, emission filters: 910Lp + 1100Lp, exposure time: 150 ms). The NIR-II imaging curves of C tumors and D total radiation efficiency of FEPT in major organs and tumors at 48 h post-injection. Tu: tumor, Lu: lung, He: heart, Ki: kidney, Sp: spleen, Li: liver. Data are presented as Mean ± SD (n = 3)