Fig. 4

In vitro and In vivo biodistribution. (A) Intracellular concentrations of Ir in HCT116 cells measured by flow cytometry at different time points after treated with Nir/Ir mixture and Nir-Ir NPs. Data were presented as mean values ± SD (n = 3 independent samples). *P < 0.05, **P < 0.01, indicated statistical difference between groups from two-tailed student’s t test. (B) Intracellular concentration of irinotecan in HCT8/V cells measured by flow cytometry at different time points after treated with Nir-Ir NPs. Data were presented as mean values ± SD (n = 3 independent samples). *P < 0.05, **P < 0.01, ***P < 0.001 indicated statistical difference between groups from two-tailed student’s t test. (C) Representative in vivo fluorescence images of mice bearing subcutaneous HCT8/V tumors intravenously injected with Nir-Ir NPs/Cy5.5 or free Cy5.5. Whole-body imaging was performed at predetermined time points. Yellow circles indicate the tumor sites. (D) Average fluorescence intensity in the tumor sites at different time points. Data were presented as mean values ± SD (n = 3 mice per group). (E) Fluorescence images of ex vivo organs and tumors excised at 24 h. (F) Average fluorescence intensity of the organs and tumors. Data were presented as mean values ± SD (n = 3 mice per group). **P < 0.01 from two-tailed student’s t test