Fig. 7.

In vivo fluorescence imaging of intratumorally administered siRNAs to tumor-xenografted mice. The BALB/c nude mice were anesthetized with 1.5−2% isoflurane, and 100 µL of 6.0 × 10⁶−1.0 × 10⁷ HeLa cells were inoculated subcutaneously on both sides of the back. After 10 days, 1 µg of free Cy3-labeled siRNA was administered intratumorally into the left tumor, and 1 µg of Cy3-labeled siRNA/S-R11 (20:1 N/P ratio) nanocomplex was administered intratumorally into the right tumor site. a The Cy3 fluorescence intensity was observed every hour for 4 h using an in vivo fluorescence imaging system. The left arrow indicated the fluorescence distribution of free siRNA, and the right arrow pointed to that of the S-R11 nanocomplex. b Relative mean fluorescence intensity and c relative integrated density (area × intensity unit) of each independent sample were analyzed using NEOimage software. The intensity at each time point was normalized with the initial intensity. The data represented mean ± standard deviation (*p < 0.05, **p < 0.01, and independent n = 4)