On the effect of Ca2+ and La3+ on the colloidal stability of liposomes
This work deals with the effect of Ca2+ and La3+ on the colloidal stability of phosphatidylcholine (PC) liposomes in aqueous media. As physical techniques, nephelometry, photon correlation spectroscopy, electrophoretic mobility, and surface tension were used. The theoretical predictions of the collo...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 21(2005), 24 vom: 22. Nov., Seite 10968-75 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2005
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Colloids Liposomes Phosphatidylcholines Lanthanum 6I3K30563S Calcium SY7Q814VUP |
| Zusammenfassung: | This work deals with the effect of Ca2+ and La3+ on the colloidal stability of phosphatidylcholine (PC) liposomes in aqueous media. As physical techniques, nephelometry, photon correlation spectroscopy, electrophoretic mobility, and surface tension were used. The theoretical predictions of the colloidal stability of liposomes were followed using the Derjaguin-Landau-Verwey-Overbeek theory. Changes in the size of liposomes and high polydispersity values were observed as La3+ concentration increases, suggesting that this cation induces the aggregation of liposomes. However, changes in polydispersity were not observed with Ca2+, suggesting a coalescence mechanism or fusion of liposomes. The stability factor (W), calculated from the nephelometry measurements indicated that aggregation/fusion occurs at a critical concentration (c.c.) of 0.3 and 0.7 M for La3+ and Ca2+, respectively. To gain a better insight into the interaction mechanism between the liposomes and the studied ions, the interaction between PC monolayers and Ca2+ and La3+ was studied. Changes in the surface area per lipid molecule (A0) in the monolayer at the c.c. values were found for both ions, with a more pronounced effect in the case of Ca2+. This corresponds with a larger reduction of the steric repulsive interaction between the headgroups at the phospholipid membrane (pi(head)). The experimental result validates the hypothesis made on the liposome fusion in the presence of Ca2+ and liposome aggregation in the presence of La3+. These aggregation mechanisms have also been confirmed by transmission electron microscopy |
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| Beschreibung: | Date Completed 05.04.2007 Date Revised 21.11.2013 published: Print Citation Status MEDLINE |
| ISSN: | 1520-5827 |