Preparation and Evaluation of Rationally Designed Polymers for Efficient Endosomal Escape of siRNA

Small interfering RNA (siRNA) showed promising prospect in the fields of basic research and drug development due to its capability in inhibition of the expression of any interest gene. However, delivery is the most complicated and challenging process that hampers the wide application of siRNA. Rapid and efficient escape of siRNA from endosome to cytoplasm constitutes a determinant factor for gene silencing. In this chapter, we provide a detailed protocol of rationally designed pH-sensitive polymeric nanomicelles with high endosomal escape efficiency that can facilitate the cytosolic release of internalized siRNA. We elaborately described the synthesis of the polymer, preparation, and characterization of the siRNA-loaded nanoparticles, the process of internalization and intracellular trafficking of nanoparticles, as well as in vitro and in vivo gene silencing and cancer treatment effects of proposed organic nanoformulation.