Sequence-defined oligoaminoamides for the delivery of siRNAs.

Since it was found that synthetic small interfering RNA (siRNA) can invoke RNA interference (RNAi) responses in mammalian cells, it has gained enormous attention as a tool for gene silencing in basic science and as a novel therapeutic modality. To develop carriers for cytosolic and systemic siRNA delivery, our laboratory has recently developed a sequence-defined polymer platform compatible with solid-phase-supported synthesis. These polymers have displayed efficient siRNA-mediated gene silencing in vitro and in vivo. In this chapter, we provide a brief background on the special features of these polymers and detailed protocols to evaluate polyplex formation, gene silencing efficiency, and cytotoxicity of siRNA-containing polyplexes.