title: Characterization of phospholipid+semifluorinated alkane vesicle system.
abstract: The aim of this study is to characterize vesicles obtained by the incorporation of the semifluorinated alkane, (perfluoro-n-hexyl)ethane (diblock F6H2) to a standard lipid, egg yolk phosphatidylcholine (PC). Large unilamellar vesicles (LUVs), prepared by extrusion, were characterized by fluorescence spectroscopy, zeta potential (zeta-potential) and light scattering. By using the fluorescence spectroscopy technique, the anisotropy of l,6-diphenyl-l,3,5-hexatriene (DPH) probe at different temperatures was determined. It was demonstrated that F6H2 is placed inside of the lipid bilayer and that the hydrocarbon acyl chain in the bilayers has higher viscosity in the presence of fluoroalkane. The zeta-potential of the PC-F6H2 system is negative and increases (in absolute value) from -10 to -19 mV when the temperature rises from 10 to 25 degrees C, this last value keeping practically constant with a further increase of temperature. The adsorption of K+ ions on the liposome surface was measured by zeta-potential. This adsorption originates a sudden increase of the initial zeta-potential followed by a slight decrease with K+ concentration. The application of the DLVO theory of colloidal stability showed a growing dependence of the DLVO potential with K+ concentration and consequently a increasing stability.
authors.affiliation: Biophysics and Interfaces Group, Department of Applied Physics, Faculty of Physics, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Sabín
authors.forename: Juan M
authors.initials: JM
authors.lastname: Ruso
authors.forename: Alfredo
authors.initials: A
authors.lastname: González-Pérez
authors.forename: Gerardo
authors.initials: G
authors.lastname: Prieto
authors.forename: Félix
authors.initials: F
authors.lastname: Sarmiento
mesh_terms: D000473:Alkanes / Q000737:chemistry* / Q000378:metabolism; D004161:Diphenylhexatriene / Q000737:chemistry / Q000378:metabolism; D005466:Fluorocarbons / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008027:Light; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism; D008823:Micelles; D010713:Phosphatidylcholines; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence; D013696:Temperature; D013816:Thermodynamics
chemical_list: D000473:Alkanes; D005466:Fluorocarbons; D008051:Lipid Bilayers; D008081:Liposomes; D008823:Micelles; D010713:Phosphatidylcholines; D004161:Diphenylhexatriene; C078626:perflexane