液晶态磷脂酰乙醇胺脂质体和LB膜结构的研究

Structure of Phosphatidylethanolamine Liposome and Langmuir-Blodgett Films in Liquid Crystalline State

用原子力显微镜、小角 X射线散射和 3 1 P NMR分别对液晶态磷脂酰乙醇胺脂质体和 LB膜结构进行了研究 .用原子力显微镜观察到了液晶态脂质体的立方相和双层膜共存的结构图像 .研究结果表明 ,两相共存的状态与双亲性分子的结构、浓度以及介质的组分和 p H等因素有关 .用小角 X射线散射和 3 1 P NMR研究发现 ,在 DEPE液晶态中 ,钠盐诱导形成 Q2 2 9(Im3m)立方相 .DEPE液晶态分别在 37.5℃出现 Lβ→Lα可逆相变 ,在 6 3.5℃出现 Lα→ H 可逆相变 .

The structure of phosphatidylethanolamine in Langmuir-Blodgett films and liposome in liquid crystalline state was investigated by means of the atomic force microscope(AFM), small angle X-ray scatting(SAXS) and 31P nuclear magnetism resonance( 31P NMR). By the atomic force microscope, some large and small lipid vesicles and a coexistent structure of cubic phase and bilayer phase of PE liposome were observed. The coexistent structure of the two phases is closely related to the structure of phospholipid, concentration, medium and pH. It was found that sodium salt solutes induce the formation of an Im3m(Q 229) cubic phase in DEPE dispersions. The phase transition of DEPE with the change of temperature was investigated. The L β→L α transitions are at 37.5 ℃ and the L α→H Ⅱ transitions are at 63.5 ℃.