Figure 4.
Higher stability of siPA-NPs relative to si-NPs corresponds to greater circulation time and increased accumulation in tumor tissue. A) siPA-NPs are more stable than si-NPs in the presence of heparin, as evaluated by FRET measurements. B) siPA-NPs injected intravenously in mice have a longer circulation half-life than si-NPs. C, D) siPA-NPs accumulate more in tumor tissue and in the MPS organs (liver and spleen) than si-NPs in a mouse tumor model at 20 minutes following tail vein injection.