Analysis of mRNA Delivery Performance via Vibrating Mesh Nebulization

Hanna Beike¹, Benjamin Heine¹ ,Gesa Bräunlich¹, David Jürgens², Thanh Mai Doan¹, Robert Pakocs¹ & Michael Hahn¹

¹PARI Pharma GmbH, Moosstraße 3, Starnberg, 82139, Germany

²RNhale GmbH, Klopferspitz 19, Planegg, 82152, Germany

Summary

This study investigates the nebulization of lipid nanoparticle (LNP)-encapsulated mRNA using five different mesh nebulizer systems, focusing on delivery efficiency, lung deposition, and preservation of mRNA integrity. With rising interest in inhaled mRNA therapies for respiratory diseases, optimizing delivery devices is critical to ensure therapeutic efficacy and minimize systemic side effects. Nebulizer performance was evaluated through aerosol characterization using Sultanol^® forte, Multiple-Path Particle Dosimetry (MPPD) modelling for lung deposition, and in vitro intracellular protein expression of pre- and post-nebulized mRNA-LNP formulation as integrity parameter. The breath-triggered eFlow Integrated exhibited the highest total output rate (TOR) and achieved the highest delivered dose (DD) of 96 %, resulting in short treatment durations. Despite similar lung deposition rates (44–50%), predicted by the MPPD model due to comparable droplet sizes and breathing patterns, cellular expression data revealed pronounced differences in mRNA integrity post-nebulization. The Aerogen Solo showed 18% relative mean fluorescence integrity (MFI) compared to the pre-nebulized formulation, while the eFlow Integrated preserved 50% of the mRNA-LNP’s biological activity. This translated into significant differences in drug efficiency and required nebulization time to reach a target expression dose, ranging from 5.8 minutes (eFlow Integrated) to 90.3 minutes (Aerogen Solo). Results highlight that device design and configuration substantially influence the functional delivery of sensitive formulations. While general-purpose nebulizers, which might not be intended to nebulize mRNAs, may be suboptimal, customizable drug-specific product platforms like eFlow OS and eFlow Integrated offer superior performance for mRNA-based inhalation therapies.