Real-time biodistribution of Cy5.5-labeled siRNA and nanoplexes.
(A) Representative biodistribution of Cy5.5-labeled siRNA in a mouse,
with the siRNA administered as an aqueous solution, unmodified HK
nanoplex or RP-HK nanoplex. Times 15, 30, 60, 120 min, and 4, 6, and
24 h are shown. Red circles encircle the tumors. (B) Fluorescence
emission localized at the tumor was measured for the different siRNA
groups. The data represent the mean ± SD of fluorescence of four
determinations for each carrier. *, P < 0.05;
**, P < 0.01; RP-HK carrier versus unmodified
HK carriers and control groups.