RNA lipid nanoparticles stabilized during nebulization through excipient selection

Nebulization of lipid nanoparticles (LNPs) has demonstrated great potential for the treatment of various pulmonary disorders <i>via</i> therapeutic RNA delivery. However, during the nebulization process, LNPs are subjected to high shear forces that result in particle destabilization and consequent loss of cargo. Here, we provide a generalizable approach to stabilize LNPs by adjusting the nebulization buffer composition. We investigated the effect of buffer composition on nanoparticle size, RNA encapsulation efficiency, and LNP material recovery. We found that pH 5.0 citrate buffer reduces the loss of encapsulated RNA, poloxamer 188 maintains nanoparticle size and improves recovery, and glucose is important for an iso-osmotic solution. RNA encapsulated in nebulized LNPs maintained bioactivity as demonstrated with cellular uptake and functional siRNA delivery to Vero cells expressing nano luciferase. Together, this work shows a versatile strategy for the delivery of inhalable LNP-based RNA therapies.