Figure 5.

Fluorescence imaging of Cy5-labelled siRNA in mouse skin. (A) Whole-body fluorescence intensity imaging of electroporation of Cy5-siRNA in mouse skin. Animals received the following treatments: (G1) siRNA was directly painted on the skin but without further treatment; (G2) animals without any treatment as negative control; (G3) electroporation at 70 V without rolling; (G4-6) electroporation at 70 V facilitated by rolling with microneedle rollers with a length of 0.5, 1.0 or 1.5 mm. Fluorescence images were merged with X-ray images to show the fluorescent sites. Electroporation conditions were: 10 electrical pulse; voltage 70 V; 10 ms pulse duration; 1 s pulse interval. (B) Quantitative analysis of (A). The mean fluorescence intensity (MFI) was calculated from 4 (6 h) or 3 (24 h) different mice. Data were normalized to unelectroporated mice whose MFIs were set to zero. Each bar represents the mean ± SEM. Statistical analyses were performed using two-tailed Student's t-test. *, vs. unelectroporated mice at the same time point, ***P <0.001. #, vs. mice electroporated without rolling at the same time point, ##P <0.01, and ###P <0.001. (C) Fluorescence imaging of isolated skin at 6 h post treatment and the corresponding quantitative analysis result. One mouse was sacrificed for examination at 6 h post electroporation for each group of mice.