Endosomal disruption by co-encapsulating gentamicin in lipid nanoparticles for efficient siRNA delivery and cancer therapy

Efficient siRNA delivery is highly desirable for disease treatment. However, the application of conventional nanoparticles is limited by the inability to escape from endo-lysosomes. Herein, we report a strategy using small-molecule drugs to enhance siRNA endo‐lysosomal release,addressing this challenge. We encapsulated gentamicin(GM) into the marketed Onpattro® formulation to establish LNP-siRNA/GM nanoparticles that promote siRNA endo‐lysosomal escape through endosomal disruption, mechanistically exhibiting unique functionality and synergistic effects of LNP-siRNA/GM to improve cancer therapy. Besides, GM induced reactive oxygen species (ROS) and phospholipids accumulation in endo‐lysosomes, as well as the physical characteristics of lipid nanoparticles (LNPs) were preserved. We also revealed that GM causes endo‐lysosomal swelling and disrupts the endosomal membrane to enable siRNA release, as confirmed by Galectin 3 recruitment and acridine orange release. This approach achieved ∼81% mRNA-EGFR silencing, which is more than LNP-siEGFR (∼56.23%) by enhancing siRNA endo‐lysosomal escape efficiency. Meanwhile, LNP-siEGFR/GM exhibited significant biological activities in HepG2 cells, driven by the synergistic effects of siEGFR and GM with the VEGF and CXCL12 downregulation of, and ROS and phospholipids upregulation. Furthermore, tumor growth was notably suppressed after intravenous injection of LNP-siEGFR/GM in tumor-bearing nude mice. The combination of EGFR-siRNA and GM could also greatly inhibit angiogenesis, be antiproliferative, and induce tumor cells apoptosis. Therefore, this GM and siRNA co-delivery system would provide an efficient strategy for siRNA endosomal escape, significantly improving knockdown in various LNPs based siRNA delivery systems and efficiently enhancing cancer therapy.