Steric-induced effects on stabilizing a lamellar structure.
We investigate the behavior of multilamellar phases composed of lecithin and a commercial cosurfactant (Simusol), which is a mixture of ethoxylated fatty acids. Using X-ray scattering and a new procedure to fit the data, relevant parameters characterizing the lamellar structure were determined as a function of membrane composition, varying from 100% of lecithin to 100% of Simulsol. Scattering data illustrating the swelling of the lamellae for different amounts of cosurfactant are presented with the respective behavior of the Caillé parameter. With this experimental approach, we show that the incorporation of ethoxy brushes onto the lipid surface enhances repulsive interactions arising from membrane fluctuations and changes the interactions at the interface between bilayers.
Instituto de Física, Universidade de São Paulo , Caixa Postal 66318, 05314-970 São Paulo, Brazil.
Barbara B
BB
Gerbelli
Rafael L
RL
Rubim
Emerson R
ER
Silva
Frédéric
F
Nallet
Laurence
L
Navailles
Cristiano L P
CL
Oliveira
Elisabeth A
EA
de Oliveira
D002462:Cell Membrane / Q000737:chemistry; D054709:Lecithins / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
D054709:Lecithins; D008051:Lipid Bilayers; D013501:Surface-Active Agents