A Dual-Targeting Delivery System for Effective Genome Editing and In Situ Detecting Related Protein Expression in Edited Cells

One of critical steps in genome editing by CRISPR-Cas9 is to deliver the CRISPR-Cas9 system into targeted cells. In this study, we developed a dual-targeting delivery system based on polymer/inorganic hybrid nanoparticles to realize highly efficient genome editing in targeted tumor cells as well as in situ detection on the related protein expression in edited cells. The CRISPR-Cas9 plasmid for CDK11 knockout was encapsulated in the core of the delivery system composed of protamine sulfate, calcium carbonate, and calcium phosphate by coprecipitation, and functional derivatives of carboxymethyl chitosan (biotinylated carboxymethyl chitosan with biotin ligands and aptamer-incorporated carboxymethyl chitosan with AS1411 ligands) were decorated on the nanovector surface by electrostatic interactions to form the dual-targeting delivery system. On the basis of the tumor cell targeting capability of biotin and AS1411 ligands as well as the nuclear targeting of AS1411, the dual-targeting system can deliver the CRISPR-Cas9 plasmid into the nuclei of tumor cells to realize highly efficient genome editing, resulting in a dramatic decrease (>90%) in CDK11 protein together with the significant downregulation of other proteins involved in tumor development, including an similar to 90% decrease in MMP-9, >40% decrease in VEGF, and similar to 70% decrease in survivin. Using the same vector, molecular beacons can be easily delivered to edited cell nuclei to in situ detect the mRNA level of related proteins (p53 and survivin as typical examples) and mRNA distribution in subcellular organelles. Our strategy can realize effective genome editing and in situ detection on related protein expression simultaneously.