title: Characterization of cationic liposomes. Influence of the bilayer composition on the kinetics of the liposome breakdown.
abstract: The cationic large unilamellar mixed liposomes from 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) and didodecyldimethylammonium bromide (DDAB) or dioctadecyldimethylammonium bromide (DODAB) were prepared. The influence of the addition of Triton X-100 (TX-100) or octaethylene glycol mono-n-dodecylether (C(12)E(8)) on the membrane integrity was investigated turbidimetrically. The stability of the liposomal systems was estimated by monitoring fluorimetrically at 25 °C the rate of spontaneous and surfactant-induced release of entrapped 5(6)-carboxyfluorescein (CF). In order to evaluate the interaction of the cationic DODAB guest with the host POPC membrane, the main phase transition temperatures (T(m)) were determined by electron paramagnetic resonance spectroscopy (EPR). All the results obtained show that the presence of DODAB and DDAB stabilizes the POPC liposomes. The extent of stabilization depends on the concentration and nature of the cationic guest.
authors.affiliation: Dipartimento di Scienze del Farmaco, Università G. d'Annunzio, 66013 Chieti, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Angelini
authors.forename: Marco
authors.initials: M
authors.lastname: Chiarini
authors.forename: Paolo
authors.initials: P
authors.lastname: De Maria
authors.forename: Antonella
authors.initials: A
authors.lastname: Fontana
authors.forename: Carla
authors.initials: C
authors.lastname: Gasbarri
authors.forename: Gabriella
authors.initials: G
authors.lastname: Siani
authors.forename: Diana
authors.initials: D
authors.lastname: Velluto
mesh_terms: D002412:Cations / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D009391:Nephelometry and Turbidimetry; D017830:Octoxynol / Q000737:chemistry; D044367:Phase Transition; D010713:Phosphatidylcholines / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D044366:Transition Temperature
chemical_list: D002412:Cations; D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D000644:Quaternary Ammonium Compounds; C046112:didodecyldimethylammonium; C015831:dimethyldioctadecylammonium; C017272:dodecyloctaethyleneglycol monoether; D011092:Polyethylene Glycols; D017830:Octoxynol; C028694:1-palmitoyl-2-oleoylphosphatidylcholine