title: Influence of temperature, anions and size distribution on the zeta potential of DMPC, DPPC and DMPE lipid vesicles.
abstract: The purpose of the work is to compare the influence of the multilamellarity, phase state, lipid head groups and ionic media on the origin of the surface potential of lipid membranes. With this aim, we present a new analysis of the zeta potential of multilamellar and unilamellar vesicles composed by phosphatidylcholines (PC) and phosphatidylethanolamines (PE) dispersed in water and ionic solutions of polarizable anions, at temperatures below and above the phase transition. In general, the adsorption of anions seems to explain the origin of the zeta potential in vesicles only above the transition temperature (Tc). In this case, the sign of the surface potential is ascribed to a partial orientation of head group moiety toward the aqueous phase. This is noticeable in PC head groups but not in PEs, due to the strong lateral interaction between PO and NH group in PE.
authors.affiliation: Laboratorio de Fisicoquímica, Dpto. de Química, INQUISUR, Universidad Nacional del Sur, Argentina.
authors.forename: M A
authors.initials: MA
authors.lastname: Morini
authors.affiliation: Laboratorio de Fisicoquímica, Dpto. de Química, INQUISUR, Universidad Nacional del Sur, Argentina.
authors.forename: M B
authors.initials: MB
authors.lastname: Sierra
authors.affiliation: Laboratorio de Fisicoquímica, Dpto. de Química, INQUISUR, Universidad Nacional del Sur, Argentina.
authors.forename: V I
authors.initials: VI
authors.lastname: Pedroni
authors.affiliation: Laboratorio de Fisicoquímica, Dpto. de Química, INQUISUR, Universidad Nacional del Sur, Argentina.
authors.forename: L M
authors.initials: LM
authors.lastname: Alarcon
authors.affiliation: Laboratorio de Fisicoquímica, Dpto. de Química, INQUISUR, Universidad Nacional del Sur, Argentina.
authors.forename: G A
authors.initials: GA
authors.lastname: Appignanesi
authors.affiliation: Laboratorio de Biointerfases, Centro de Investigación y Transferencia, de Santiago del Estero, Argentina. Electronic address: disalvoanibal@yahoo.com.ar.
authors.forename: E A
authors.initials: EA
authors.lastname: Disalvo
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D000838:Anions / Q000737:chemistry; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D004553:Electric Conductivity; D008051:Lipid Bilayers / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D010316:Particle Size; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D055672:Static Electricity; D013696:Temperature; D053835:Unilamellar Liposomes / Q000737:chemistry
chemical_list: D000838:Anions; D008051:Lipid Bilayers; D010714:Phosphatidylethanolamines; D053835:Unilamellar Liposomes; D015060:1,2-Dipalmitoylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine; C018525:1,2-dimyristoylphosphatidylethanolamine
keywords: Anions; Multilamellar vesicles; Phospholipids; Unilamellar vesicles; Water; Zeta potential