Virus-Mimicking Chimaeric Polymersomes Boost Targeted Cancer siRNA Therapy In Vivo

Small interfering RNA (siRNA) offers a highly selective and effective pharmaceutical for various life-threatening diseases, including cancers. The clinical translation of siRNA is, however, challenged by its short plasma life, poor cell uptake, and cumbersome intracellular trafficking. Here, cNGQGEQc peptide-functionalized reversibly crosslinked chimaeric polymersomes (cNGQ/RCCPs) is shown to mediate high-efficiency targeted delivery of Polo-like kinase1 specific siRNA (siPLK1) to orthotopic human lung cancer in nude mice. Strikingly, siRNA is completely and tightly loaded into the aqueous lumen of the polymersomes at an unprecedentedly low N/P ratio of 0.45. cNGQ/RCCPs loaded with firefly luciferase specific siRNA (siGL3) or siPLK1 are efficiently taken up by alpha(3)beta(1)-integrin-overexpressing A549 lung cancer cells and quickly release the payloads to the cytoplasm, inducing highly potent and sequence-specific gene silencing in vitro. The in vivo studies using nude mice bearing orthotopic A549 human lung tumors reveal that siPLK1-loaded cNGQ/RCCPs boost long circulation, superb tumor accumulation and selectivity, effective suppression of tumor growth, and significantly improved survival time. These virus-mimicking chimaeric polymersomes provide a robust and potent platform for targeted cancer siRNA therapy.