Targeted Delivery of siRNA Therapeutics to Malignant Tumors

Figure 4

Aptamer mediated delivery of siRNA. (a) Aptamers and siRNAs have been conjugated with one another to form a chimera (upper). To enhance lysis of endosomes and minimize formation of polyplexes, aptamer-siRNA conjugates have been complexed to double stranded DNA domain- (DSD-) polyhistidine conjugates (lower). Upon entry into acidic endosomes, the polyhistidine component becomes protonated which aids in the lysis of endosomes. (b) Alternatively, aptamers have been conjugated to the surface of core particles (i.e., liposomes, polyplexes) that have incorporated siRNA.

(a)

(b)