title: Influence of the preparation route on the supramolecular organization of lipids in a vesicular system.
abstract: A confocal fluorescence microscopy-based assay was used for studying the influence of the preparation route on the supramolecular organization of lipids in a vesicular system. In this work, vesicles composed of cholesterol and CTAB (1/1 mol %) or cholesterol and DOPC (2/8 mol %) and incorporating two membrane dyes were prepared by either a compressed fluid (CF)-based method (DELOS-susp) or a conventional film hydration procedure. They were subsequently immobilized and imaged individually using a confocal fluorescence microscope. Two integrated fluorescence intensities, I(dye1) and I(dye2), were assigned to each tracked vesicle, and their ratio, I(dye1)/I(dye2), was used for quantifying the degree of membrane inhomogeneity between individual vesicles within each sample. A distribution of I(dye1)/I(dye2) values was obtained for all the studied vesicular systems, indicating intrasample heterogeneity. The degree of inhomogeneity (DI) was similar for Chol/DOPC vesicles prepared by both procedures. In contrast, DI was more than double for the hydration method compared to the CF-based method in the case of Chol/CTAB vesicles, which can suffer from lipid demixing during film formation. These findings reveal a more homogeneous vesicle formation path by CFs, which warranted good homogeneity of the vesicular system, independently of the lipid mixture used.
authors.affiliation: Department of Molecular Nanoscience and Organic Materials (ICMAB-CSIC), Bellaterra, 08193, Spain.
authors.forename: Elisa
authors.initials: E
authors.lastname: Elizondo
authors.forename: Jannik
authors.initials: J
authors.lastname: Larsen
authors.forename: Nikos S
authors.initials: NS
authors.lastname: Hatzakis
authors.forename: Ingrid
authors.initials: I
authors.lastname: Cabrera
authors.forename: Thomas
authors.initials: T
authors.lastname: Bjørnholm
authors.forename: Jaume
authors.initials: J
authors.lastname: Veciana
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Stamou
authors.forename: Nora
authors.initials: N
authors.lastname: Ventosa
mesh_terms: D008055:Lipids / Q000737:chemistry*; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010316:Particle Size; D013499:Surface Properties
chemical_list: D008055:Lipids; D046911:Macromolecular Substances