Lipid bilayer elasticity measurements in giant liposomes in contact with a solubilizing surfactant.
A new method to probe the modification of the elasticity of phospholipid bilayers is presented. The purpose here concerns the action of a solubilizing surfactant on a vesicle bilayer. This method is based on the measure of the under-field elongation of giant magnetic-fluid-loaded liposomes. The addition of the nonionic surfactant octyl-beta-d-glucopyranoside (OG) to vesicles at sublytic levels increases the elasticity of the membrane, as shown by the value of the bending modulus K(b), which decreases. K(b) measured around 20 kT for a pure 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayer indeed reaches a few kT in the case of the mixed OG-DOPC bilayer. The purpose and interest of this study are to allow the determination of the membrane bending modulus before and after the addition of OG on the same magnetic liposome. Moreover, the experimental conditions used in this work allow the control of lipid and surfactant molar fractions in the mixed aggregates. Then, optical microscopy observation can be performed on samples in well-defined regions of the OG-phospholipid state diagram.
Ménager
Christine
C
Laboratoire des Liquides Ioniques et Interfaces Chargées, UMR 7612, Université Pierre et Marie Curie, ESPCI, CNRS, 4 place Jussieu, case 51, 75005 Paris, France. menager@ccr.jussieu.fr
Guemghar
Dihya
D
Perzynski
Régine
R
Lesieur
Sylviane
S
Cabuil
Valérie
V
D004548:Elasticity; D005947:Glucose / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D008280:Magnetics; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry*
D008051:Lipid Bilayers; D008081:Liposomes; D013501:Surface-Active Agents; D005947:Glucose