Fig. 6: Interaction of LNPs with anionic LUVs.

a Schematic representation of the FRET based lipid mixing assay. LNPs are mixed with anionic acceptor liposomes containing two lipid conjugated fluorophores (PE-NBD and PE-LR), after which the dequenching of PE-NBD is measured over time. b Lipid mixing results of LNPs (250 µM) mixed with anionic LUVs (125 µM) at pH 6.0 and 7.4 cryoTEM, performed at 37 °C for 25 minutes. Plotted data is the average of a triplicate in which error bars represent the standard deviation. c Schematic representation of the structural analysis of lipid mixing between LNPs and LUVs. CryoTEM imaging was performed after an incubation of 1 hour at 37 °C. Similarly, SAXS measurements over a time span of 6 hours were started after an incubation of 1 hour at 37 °C. d, e SAXS profiles of 10PE-LNP-NP1 or 49PE-LNP-NP1 mixed with LUVs. f, g Representative cryoTEM images of 10PE-LNP-NP1 or 49PE-LNP-NP1 mixed with LUVs. Micrographs are a representative selection from a duplicate of experiments. Scale bars are 100 nm. h Schematic representation of the interaction of LNPs with LUVs, depicting the change in situ transition from lamellar to inverted phases for 10PE-LNP-NP1, where the pre-programmed hexagonal phases in the 49PE-LNP-NP1 remains intact. Abbreviations used: NP Nitrogen to phosphate ratio, LUV large unilamellar vesicle, FRET Fluorescence resonance energy transfer. Source data are provided as a Source Data file.