TY  - JOUR
AU  - Philipp, Julian
AU  - Dabkowska, Aleksandra
AU  - Reiser, Anita
AU  - Frank, Kilian
AU  - Krzysztoń, Rafał
AU  - Brummer, Christiane
AU  - Nickel, Bert
AU  - Blanchet, Clement E.
AU  - Sudarsan, Akhil
AU  - Ibrahim, Mohd
AU  - Johansson, Svante
AU  - Skantze, Pia
AU  - Skantze, Urban
AU  - Östman, Sofia
AU  - Johansson, Marie
AU  - Henderson, Neil
AU  - Elvevold, Kjetil
AU  - Smedsrød, Bård
AU  - Schwierz, Nadine
AU  - Lindfors, Lennart
AU  - Rädler, Joachim O.
TI  - pH-dependent structural transitions in cationic ionizable lipid mesophases are critical for lipid nanoparticle function
JO  - Proceedings of the National Academy of Sciences of the United States of America
VL  - 120
IS  - 50
SN  - 0027-8424
CY  - Washington, DC
PB  - National Acad. of Sciences
M1  - PUBDB-2024-00898
SP  - e2310491120
PY  - 2023
AB  - Lipid nanoparticles (LNPs) are advanced core-shell particles for messenger RNA (mRNA) based therapies that are made of polyethylene glycol (PEG) lipid, distearoylphosphatidylcholine (DSPC), cationic ionizable lipid (CIL), cholesterol (chol), and mRNA. Yet the mechanism of pH-dependent response that is believed to cause endosomal release of LNPs is not well understood. Here, we show that eGFP (enhanced green fluorescent protein) protein expression in the mouse liver mediated by the ionizable lipids DLin-MC3-DMA (MC3), DLin-KC2-DMA (KC2), and DLinDMA (DD) ranks MC3 ≥ KC2 > DD despite similar delivery of mRNA per cell in all cell fractions isolated. We hypothesize that the three CIL-LNPs react differently to pH changes and hence study the structure of CIL/chol bulk phases in water. Using synchrotron X-ray scattering a sequence of ordered CIL/chol mesophases with lowering pH values are observed. These phases show isotropic inverse micellar, cubic Fd3m inverse micellar, inverse hexagonal and bicontinuous cubic Pn3m symmetry. If polyadenylic acid, as mRNA surrogate, is added to CIL/chol, excess lipid coexists with a condensed nucleic acid lipidphase. The next-neighbor distance in the excess phase shows a discontinuity at the Fd3m inverse micellar to inverse hexagonal transition occurring at pH 6 with distinctly larger spacing and hydration for DD vs. MC3 and KC2. In mRNA LNPs, DD showed larger internal spacing, as well as retarded onset and reduced level of DD-LNP-mediated eGFP expression in vitro compared to MC3 and KC2. Our data suggest that the pH-driven Fd3m- transition in bulk phases is a hallmark of CIL-specific differences in mRNA LNP efficacy.
LB  - PUB:(DE-HGF)16
C6  - pmid:38055742
UR  - <Go to ISI:>//WOS:001498765900001
DO  - DOI:10.1073/pnas.2310491120
UR  - https://bib-pubdb1.desy.de/record/603710
ER  -