Figure 5.

Tumor-specific delivery of the nanotherapeutics in a CAC mouse model. (A) Representative ex vivo fluorescence images for the evaluation of nanoparticle distribution in the major organs. C57BL/6 mice were intravenously injected with AOM followed by ad libitum administration of a 2% solution of DSS in drinking water for three cycles. This protocol allowed nearly all mice to develop tumors in the colonic tissues after 70 days. The mice with tumors were orally administered Cy5.5-labeled nSN38 (termed Cy5.5-nSN38). A solution containing free Cy5.5 was also orally administered as a reference. (B and C) Ex vivo imaging of the whole colons (B) and tumors (C) excised from CAC mice at 6 and 24 h postadministration. (D) Quantification of fluorescence intensities of colorectal tumors. Confocal microscopy images (E) and fluorescence intensities (F) of colorectal tissue sections harvested at 6 and 24 h after oral administration. The red and blue signals indicate Cy5.5 and nuclei counterstained with DAPI, respectively. The data are presented as the mean ± SD. *p < 0.05 and **p <0.01, as determined by two-way ANOVA followed by Bonferroni's post hoc test.