Optimization of Aerosolizable Messenger RNA Lipid Nanoparticles for Pulmonary Delivery

Messenger RNA (mRNA)-based vaccines and treatments have recently emerged as a promising strategy.Naked mRNA presents various limitations for direct delivery.Therefore, in this paper, Lipid Nanoparticles (LNPs) were utilized for the delivery of mRNA.Lipid nanoparticle (LNP) mRNA systems are highly effective as vaccines, but their efficacy for pulmonary delivery has not yet been fully established.Additionally, research on effective delivery systems and administration methods for vaccines is required to resolve the stability and degradation issues associated with naked mRNA delivery.This study aimed to determine mRNA delivery efficiency via the inhalation of a lipid nanoparticle (LNP) formulation designed specifically for pulmonary delivery.To this purpose, we built a library of seven LNP configurations with different lipid molar and N/P ratios and evaluated their encapsulation efficiency using gel retardation assay.Among the tested LNPs, LNP1, LNP2-2, and LNP3-2 demonstrated high transfection efficiency in vitro based on FACS analyses luciferase assays, and intracellular accumulation tests.The mRNA delivery efficiencies of the selected LNPs after inhalation and intravenous injection were compared and evaluated.LNP2-2 showed the highest mRNA expression in healthy mouse lungs when aerosolized and was found to be non-toxic.These results indicate that LNP2-2 is a promising carrier for lung mRNA delivery via inhalation.