Lipid nanoparticle topology regulates endosomal escape and delivery of RNA to the cytoplasm

RNA therapeutics have the potential to resolve a myriad of diseases caused by gene deficiency. Lipid nanoparticles (LNPs) are one of the most successful RNA delivery systems. However, expanding their application hinges on the discovery of next generation LNPs with high potency, cyto-specific targeting, and low side effects. Overcoming the difficulty of releasing cargo from endocytosed LNPs remains a significant hurdle. The endosomal escape of viral and non-viral nanoparticles relies on the topological transformation of membrane fusion pore formation followed by RNA translocation into the cytosol. In this study we show that LNP-RNA nanostructure modulates the energetic cost of LNP fusion with a target membrane. The inclusion of a new class of structurally-active lipids leads to superior LNP endosomal fusion, fast evasion of endosomal entrapment, and efficacious RNA delivery. Specifically, bicontinuous cubic RNA-LNPs, cuboplexes , have significantly higher endosomal escape rates and deliver more RNA compared to regular lamellar LNPs.