INQUISUR   21779
INSTITUTO DE QUIMICA DEL SUR
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Proposal about zeta potentials origin in liposomes prepared with zwitterionic lipids
Autor/es:
MARCELA A. MORINI; MARIA BELEN SIERRA; VIVIANA I. PEDRONI; LAUREANO ALARCON; GUSTAVO A. APPIGNANESI; ANIBAL DISALVO
Lugar:
Sierra de la Ventana
Reunión:
Congreso; XLIII Reunión Anual de la Sociedad Argentina de Biofísica; 2014
Institución organizadora:
UNS - IFISUR
Resumen:
We measured the zeta potentials of MLVs and LUVs liposomes of DMPC, DPPC and DMPE dispersed in water, in KCl (1 mM) and in KClO4 (1mM) at pH 7.4 and temperatures according to its solid-crystalline and liquid-crystalline states. Liposomes used are composed of neutral lipids, each having one phosphatidyl group and one choline group in their molecules. In spite of this fact, the liposomes exhibit non-zero mobility in an external electric field, thus these liposomes have non-zero surface electric potentials. In this work we chose water as dispersing medium of liposomes to exclude the possibility of ion adsorption onto the liposome surfaces in order to investigate possible changes in the zeta potential caused by increases of ionic strength, being low but comparatively higher than that of water. Two main models can be found in literature about surface charge. Our observations in presence and absence of ions are in better agreement with the orientation of the lipid head group in the liposome surface region (1,2) than with the proposal about adsorption of ions onto liposomes as responsible of this charge (3).