摘要

Effectively activating macrophages to 'eat' tumor cells have great potential in cancer immunotherapy. However, tumor cells can express CD47 to evade macrophages, and secrete immunosuppressive factors to polarize macrophages into a pro-tumorigenic M2 phenotype. Herein, PEI-coated Au nanorods with an inherent capability to induce calreticulin (CRT) exposure were prepared and then used to electrostatically adsorb the CRISPR/Cas9 plasmid pH330/sgCD47, generating AuPpH330/sgCD47 nanocomplexes. The efficient induction of CRT exposure by AuPpH330/sgCD47 nanocomplexes provides additional "eat-me" signals to macrophages, especially under a 1064 nm laser. Meanwhile, AuPpH330/sgCD47 nanocomplexes under a 1064 nm laser activated the HSP70 promoter of pH330/sgCD47 to drive CD47 genomic disruption to suppress "don't eat-me" signals. Therefore, AuPpH330/sgCD47 treatment synergistically promoted the macrophage phagocytosis of tumor cells and increased M2-to-M1 macrophage repolarization, which stimulates a potent immune response to inhibit tumor growth and lung metastasis. These HSP70 promoter-driven genetically edited nanoparticles represent a promising strategy for macrophage-mediated cancer immunotherapy.