Mechanistic Studies of an Automated Lipid Nanoparticle Reveal Critical Pharmaceutical Properties Associated with Enhanced mRNA Functional Delivery In Vitro and In Vivo. Issue 9 (16th December 2021)

• Record Type: Journal Article
• Authors: Cui, Lili; Hunter, Morag R.; Sonzini, Silvia; Pereira, Sara; Romanelli, Steven M.; Liu, Kai; Li, Weimin; Liang, Lihuan; Yang, Bin; Mahmoudi, Najet; Desai, Arpan S.
• Is Part Of: Small. Volume 18:Issue 9(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-16
• Subjects: hydrophobic surfaces -- lipid nanoparticles -- macropinocytosis -- mRNA loading -- particle size; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202105832
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Recently, lipid nanoparticles (LNPs) have attracted attention due to their emergent use for COVID‐19 mRNA vaccines. The success of LNPs can be attributed to ionizable lipids, which enable functional intracellular delivery. Previously, the authors established an automated high‐throughput platform to screen ionizable lipids and identified that the LNPs generated using this automated technique show comparable or increased mRNA functional delivery in vitro as compared to LNPs prepared using traditional microfluidics techniques. In this study, the authors choose one benchmark lipid, DLin‐MC3‐DMA (MC3), and investigate whether the automated formulation technique can enhance mRNA functional delivery in vivo. Interestingly, a 4.5‐fold improvement in mRNA functional delivery in vivo by automated LNPs as compared to LNPs formulated by conventional microfluidics techniques, is observed. Mechanistic studies reveal that particles with large size accommodate more mRNA per LNP, possess more hydrophobic surface, are more hemolytic, bind a larger protein corona, and tend to accumulate more in macropinocytosomes, which may quantitatively benefit mRNA cytosolic delivery. These data suggest that mRNA loading per particle is a critical factor that accounts for the enhanced mRNA functional delivery of automated LNPs. These mechanistic findings provide valuable insight underlying the enhanced mRNA functional delivery to accelerate future mRNA LNP product development. Abstract : A key finding of the manuscript is that previously observed enhanced mRNA functional delivery mediated by automated lipid nanoparticles (LNPs) in cells is reproduced in mice. Mechanistic studies indicate that mRNA copies per particle are critical for mRNA cytosolic delivery. Additionally, particle size, hydrophobic surface, hemolysis, protein corona, and macropinocytosis may collectively contribute to the improved mRNA functional delivery.