‘Tripod-like’ lung-targeting (LuT) lipids for highly efficient and selective LNPs for gene delivery and editing

Abstract Developing lung-targeting delivery systems is essential for treating pulmonary conditions such as genetic respiratory diseases, infections, fibrosis and cancer. We synthesized and evaluated 444 lung-targeting lipids (LuT lipids) that form lipid nanoparticles (LNPs) to efficiently deliver messenger RNA and CRISPR–Cas9 genome editors to lungs with minimal side effects. Empirical analyses revealed structure–activity relationships, with top-performing LuT lipids possessing a unique ‘tripod-like’ structure consisting of a quaternary amine head, three long alkyl chains as legs and a short chain as a handle. LuT lipids improved endosomal escape, cargo release and endogenous targeting via adsorption of plasma proteins. Lead 1A7B13 LNPs showed a 25.5-fold improvement in mRNA delivery and a 9.2-fold increase in CRISPR–Cas9 gene-editing efficiency compared to benchmark DOTAP SORT LNPs, achieving over 90% selectivity to the lungs. 1A7B13 LNPs effectively delivered IL-10 mRNA in a therapeutic model of acute lung injury. This study reveals the relationship between lipid structure and lung-targeting activity, enriching the toolkit for lung-specific carriers.