Lipid shape and packing are key for optimal design of pH-sensitive mRNA lipid nanoparticles

• 成果类型: Article
• 署名作者: Tesei, Giulio; Hsiao, Ya -Wen; Dabkowsk, Aleksandra; Groenberg, Gunnar; Arteta, Marianna Yanez; Ulkoski, David; Bray, David J.; Trulsson, Martin; Ulandef, Johan; Lund, Mikael; Lindfors, Lennart
• 署名单位: University of Copenhagen; University of Copenhagen; Lund University; STFC Daresbury Laboratory; UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC); AstraZeneca; AstraZeneca; AstraZeneca
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9587
• DOI: 10.1073/pnas.2311700120
• 发表日期: 2024-01-09
• 关键词: single-stranded rna; molecular-dynamics; force-field; delivery; release; phase; DRUG; gui

摘要

The ionizable-lipid component of RNA-containing nanoparticles controls the pH-dependent behavior necessary for an efficient delivery of the cargo-the so-called endosomal escape. However, it is still an empirical exercise to identify optimally performing lipids. Here, we study two well-known ionizable lipids, DLin-MC3-DMA and DLin-DMA using a combination of experiments, multiscale computer simulations, and electrostatic theory. All -atom molecular dynamics simulations, and experimentally measured polar headgroup p/C, values, are used to develop a coarse-grained representation of the lipids, which enables the investigation of the pH-dependent behavior of lipid nanoparticles (LNPs) through Monte Carlo simulations, in the absence and presence of RNA molecules. Our results show that the charge state of the lipids is determined by the interplay between lipid shape and headgroup chemistry, providing an explanation for the similar pH-dependent ionization state observed for lipids with headgroup p/C, values about one-pH-unit apart. The pH dependence of lipid ionization is significantly influenced by the presence of RNA, whereby charge neutrality is achieved by imparting a finite and constant charge per lipid at intermediate pH values. The simulation results are experimentally supported by measurements of alpha-carbon C-13-NMR chemical shifts for eGFP mRNA LNPs of both DLin-MC3-DMA and DLin-DMA at various pH conditions. Further, we evaluate the applicability of a mean-field Poisson-Boltzmann theory to capture these phenomena.