Safety concerns regarding lung-targeted lipid nanoparticles (LNPs) remain a critical issue in mRNA-based therapy. In this study, we present a lung-targeted LNP formulation, developed using the ionizable cationic lipid Lipid-392, that demonstrates both high efficacy and safety. Through systematic optimization of the LNP composition, including the components, N/P ratio, and formulation buffers, we created a simplified targeted LNP, termed Lipid-392 stLNP. This optimized Lipid-392 stLNP exhibits exceptional lung delivery efficiency with over a 100-fold improvement compared to the initial formulation. The targeting specificity of Lipid-392 stLNP reaches up to 99%, highlighting its precise pulmonary targeting. Importantly, the formulation was well tolerated even at a high dose of 12 mg/kg. In vivo studies demonstrate that Lipid-392 stLNP efficiently delivers mRNA to both endothelial and epithelial cells, achieving gene editing efficiencies of ∼70%. Notably, repeated administrations did not reduce the mRNA delivery efficiency, emphasizing its potential for use in multidose therapeutic regimens. Further validation is provided in an acute lung injury (ALI) model, where the delivery of IL-10 mRNA significantly reduces the inflammatory response. Furthermore, Lipid-392 stLNP facilitates efficient gene editing by co-delivering ABE mRNA and sgRNA as well as delivering siRNA for gene silencing, with a median effective dose (ED) of approximately 0.05 mg/kg. Taken together, these findings establish Lipid-392 stLNP as a safe, efficient, and versatile platform for lung-targeted RNA delivery with broad therapeutic potential for various diseases and promising translational applications. 50
