PERMEABILITY ALTERATIONS IN UNILAMELLAR LIPOSOMES DUE TO BETAINE-TYPEZWITTERIONIC AND ANIONIC SURFACTANT MIXED SYSTEMS

Citation
A. Delamaza et Jl. Parra, PERMEABILITY ALTERATIONS IN UNILAMELLAR LIPOSOMES DUE TO BETAINE-TYPEZWITTERIONIC AND ANIONIC SURFACTANT MIXED SYSTEMS, Journal of the American Oil Chemists' Society, 70(7), 1993, pp. 685-691
Citations number
33
Categorie Soggetti
Food Science & Tenology","Chemistry Applied
ISSN journal
0003021X
Volume
70
Issue
7
Year of publication
1993
Pages
685 - 691
Database
ISI
SICI code
0003-021X(1993)70:7<685:PAIULD>2.0.ZU;2-J
Abstract
The alterations caused by betaine-type zwitterionic and anionic surfac tant mixed systems in the permeability of unilamellar liposomes have b een investigated. The partition coefficient of these systems, at diffe rent molar fractions, between the aqueous phase and the lipid bilayer of liposomes has been determined. These surfactant mixed systems were formed by N-dodecyl-N,N-dimethylbetaine (C-12-Bet) and sodium dodecyl sulfate (SDS) in the presence of 20 mM PIPES buffer and 110 mM Na2SO4, at pH 7.21. Unilamellar liposomes were prepared from egg phosphatidyl choline and phosphatidic acid (9:1 molar ratio). The release of the fl uorescent agent 5-(6)carboxyfluorescein induced by the systems has bee n studied at sub-solubilizing concentrations. When the molar fraction of C-12-Bet/SDS is about 0.4, the critical micelle concentration value s of these systems exhibit a minimum, whereas their partition coeffici ent between the aqueous phase and lipid bilayer of lipid bilayers show s a maximum. There is a consistent correlation between the partition c oefficient and the ability of the different systems of surfactants to modify the permeability of liposomes.