Fig. 2: In vivo fluorescence imaging in the NIR-IIb window and biodistribution of QD-Cat-RGD.
a, b Whole-body and high-magnification fluorescent images of 4T1 tumor-bearing mice intravenously injected with QD-Cat-RGD (a) or QD-Cat (b) nanoprobes at different time points (5 min, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h) in the NIR-IIb window. Scale bars = 5 mm. The excitation power density was 50 mW cm−2 provided by an 808 nm laser. c Serial sections of tumor tissue imaged in the NIR-IIb window or stained with H&E. Scale bars = 1 mm. The excitation power density for NIR-IIb fluorescence imaging was 25 mW cm−2 provided by an 808 nm laser. The fluorescent images in the NIR-IIb window (a–c) were representative of those generated from three mice each group. d The T (tumor)/NT (nontumor) ratio of QD-Cat-RGD or QD-Cat at different time points (5 min, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h). e The blood concentration of Pb in BALB/c mice at different time points (0.5, 1, 3, 8, 24, 48, 72 h) after intravenous injection with QD-Cat-RGD nanoprobes. f Delivery efficiency for injected dose (ID) of QD-Cat-RGD or QD-Cat in tumors and main organs (livers, spleens, lungs, and kidneys) of mice injected with QD-Cat-RGD or QD-Cat at 24 h p.i. g The protein expression level of HIF-1α in 4T1 tumor tissue in mice at 24 h after intravenous injection with PBS (control), QD-RGD (150 μL, 2 mg mL−1), and QD-Cat-RGD (150 μL, 2 mg mL−1) measured by western blot analysis. Western blot was done thrice. All data are shown as the mean ± s.e.m. of (n = 3) and n represents the number of independent samples. Statistical significance was calculated via two-tailed Student’s t-test (f) and one-way ANOVA with Tukey’s multiple comparisons test (g). NIR-IIb near-infrared IIb. Source data are provided as a Source Data file.
