Figure 2.

Chemical configurations of siRNA ^Ifngr1 1641 for gene silencing in mouse skin

(A) Schematic of the chemical structures of hydrophobically conjugated (DCA; tri-myristic acid, Myr-t) and Dio siRNAs; DCA and Myr-t conjugates are covalently linked to the 3′ end of sense strand; the two sense strands of the Dio scaffold are covalently linked by a tetraethylene glycol; the study also included unconjugated siRNA ^Ifngr1 1641 and DCA conjugated NTC siRNAs. (B) Ifngr1 mRNA silencing in skin at the injection site; mice (n = 5 per group) were injected subcutaneously (between shoulders) with a single dose of siRNA (20 mg/kg); local skin was collected at 1 week after injection and mRNA levels were measured using QuantiGene 2.0 assays; Ifngr1 expression was normalized to a housekeeping gene Ppib; data are represented as percent of PBS control (mean ± standard deviation) and analyzed by Kruskal-Wallis test (∗p < 0.05, ∗∗p < 0.01; ns, not significant). (C) Efficacy of a single dose versus two doses (2×, 24 h apart; n = 5) of DCA-siRNA ^Ifngr1 1641 (One-way ANOVA, ∗p < 0.05, ∗∗p < 0.01). bDNA, branched DNA.