Fig. 3: Temporal dynamics of HS201 and VP distribution in human BC xenografts-bearing mice.

a nIR signal from MDA-MB-231 tumor-bearing mice injected with HS201 or VP. HS201 or VP (10 nmol) were administered via tail vein, and nIR signals from tumor areas were detected by the LI-COR Pearl imager at 700 nm channel over time (pre-injection, immediate, 3, 6, 12, 24, 48, 96, and 168 h after injection). b Temporal dynamics of nIR signal from MDA-MB-231 tumors by in vivo imaging. Fluorescence intensities were monitored for individual tumors over time by Pearl Imager and average values (n = 5 mice) are plotted. Half-life of the nIR signal in the tumor site for HS201 and VP was 50 and 13 h, respectively. The ratios of nIR signals detected at the tumor site and background skin around the ear were also calculated and the average values (n = 5 mice) were plotted. Data are expressed as means ± SEM. c Ex vivo imaging of MDA-MB-231 tumors. Mice administered 10 nmol of HS201 or VP were sacrificed at the 24 h time point (5 mice for each VP and HS201 group, 3 mice for control group) to harvest the tumors. nIR signals from excised tumors and their cut surfaces were measured using the Pearl Imager at the 700 nm channel. Three representative tumors from each group are shown. In the two graphs, mean nIR signal intensities of the tumor surface and cut surface are shown. Kruskal–Wallis test was performed followed by non-parametric Dunnett multiple comparisons. d Confocal microscope images of excised MDA-MB-231 tumors. MDA-MB-231 tumors were harvested 1, 3, 6 or 12 h after the PS injection. Tumors were fixed overnight in formalin before sectioning. Samples were stained with WGA Alexa Fluor 488 conjugate membrane staining dye and DAPI and observed using a ZEISS LSM880 confocal microscope. nIR signals from photosensitizers are shown in magenta color. Mean fluorescence intensities of nIR signals for tile scanned large tumor sections are shown in each microscope image. Original magnification: Objective 40×. The scale bar indicates 15 μm.