Bispecific, Exosome‐Mimetic Lipid Nanoparticles Facilitate Dual siRNAs for Synergistic Therapy against Pancreatic Cancer

Abstract While RNA therapeutics hold great promise for combating pancreatic ductal adenocarcinoma (PDAC), the limited therapy outcome due to the insufficient delivery efficiency of vehicles and inadequate innate therapeutic potency for single siRNA hinders the broader application. Herein, report bispecific, exosome‐mimetic lipid nanoparticles (EM‐LNPs) carrying high loads of siKras and siTP53, which can efficiently overcome layers of barriers to accumulate cytoplasm in vitro and in vivo and achieve synergistic treatment for PDAC tumors. EM‐LNPs inherit features of synthetic LNPs and the protein characteristics of exosomes with outer CD47 proteins, membrane‐inserted integrin α6β4, and connexin 43. The siRNAs‐loaded EM‐LNPs can efficiently evade the host immune clearance in the circulation, considerably accumulate and penetrate dense tumors, and simultaneously target EGFR/VEGF of PDAC cells, following leakage into the cytoplasm. The intracellular siKras and siTP53 achieved synergistic therapeutic effects for PDAC cells with as high as 20 times enhancement in vitro and 3.5 times increase in vivo, significantly suppressed xenograft PDAC tumors, considerably reduced lung metastasis, and vastly extended mice survival at a low injection dose. These results explore an approach for delivering multiple gene cargoes to dense PDAC tumors for synergistic therapeutics.