Ménager Christine, Guemghar Dihya, Perzynski Régine, Lesieur Sylviane, Cabuil Valérie
Laboratoire des Liquides Ioniques et Interfaces Chargées, UMR 7612, Université Pierre et Marie Curie, ESPCI, CNRS, 4 place Jussieu, case 51, 75005 Paris, France.
Langmuir. 2008 May 6;24(9):4968-74. doi: 10.1021/la703807t. Epub 2008 Mar 26.
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.
提出了一种探测磷脂双层弹性修饰的新方法。这里的目的涉及增溶表面活性剂对囊泡双层的作用。该方法基于对负载巨磁流体的脂质体在磁场下伸长的测量。在亚裂解水平向囊泡中添加非离子表面活性剂辛基-β-D-吡喃葡萄糖苷（OG）会增加膜的弹性，如弯曲模量K(b)的值所示，该值减小。对于纯的1,2-二油酰基-sn-甘油-3-磷酸胆碱（DOPC）双层，在20 kT左右测得的K(b)在OG-DOPC混合双层的情况下确实达到了几kT。本研究的目的和意义在于能够在同一磁性脂质体上测定添加OG前后的膜弯曲模量。此外，本工作中使用的实验条件允许控制混合聚集体中脂质和表面活性剂的摩尔分数。然后，可以在OG-磷脂状态图的明确区域对样品进行光学显微镜观察。
