Synthesis and Characterization of pH-Responsive Copolypeptides Vesicles for siRNA and Chemotherapeutic Drug Co-Delivery.

Novel diblock copolypeptides are synthesized and evaluated as a pH-sensitive drug delivery vector for anticancer drugs and siRNA co-delivery. The synthetic process involve the ring opening polymerization of α-amino acid N-carboxyanhydrides as well as aminolysis and deprotection reactions, and the structures are characterized. The copolypeptides can self-assemble into stable vesicles at neutral pH, and disassemble in acidic endosomal/lysosomal, which shown the pH-responsive behavior. The cell uptake results indicated that the vesicles can co-deliver DOX and siRNA inside the same cell and exhibit a pH-sensitive release behavior. Therefore, the novel polymeric vesicles are a promising carrier for co-delivery anticancer drug and siRNA to overcome the drug resistance and enhance cancer treatment.