LiposomesUnilamellar LiposomesPhosphatidylcholinesDrug Carriers1,2-DipalmitoylphosphatidylcholineLipid BilayersCholesterolPhospholipidsKineticsPhosphatidylethanolaminesDimyristoylphosphatidylcholineMembranes, ArtificialMembrane LipidsPhosphatidylglycerolsFluoresceinsMembrane FluidityPhosphatidylserinesSpectrometry, FluorescenceMembrane FusionParticle SizeScattering, RadiationCalorimetry, Differential ScanningSphingomyelinsPolyethylene GlycolsPermeabilityFreeze FracturingLauratesMicellesBiophysicsFluorescent DyesPhase TransitionTemperatureLipidsBiophysical PhenomenaDrug Delivery SystemsDiphenylhexatriene2-NaphthylamineProteolipidsMolecular ConformationHydrogen-Ion ConcentrationCationsCell Membrane