MPEG胆甾醇酯与卵磷脂作用的LB技术研究

Interactions Between MPEG Cholesterol Esters and Phospholipid Studied by Langmuir Balance

采用酰氯法合成了3种不同分子量的高分子表面活性剂端甲基聚乙二醇胆甾醇酯(mPEG-chol),并用表面张力法测得其临界胶束浓度(CMC)值。结果表明,随着PEG链长的增加,其CMC值逐渐增大。同时,利用LB膜天平研究了3种mPEG-chol在空气/水界面上单分子膜的π-A等温曲线及其与磷脂单分子膜的相互作用。结果表明,PEG的链长不仅决定了胆甾醇酯在空气/水界面上的表面性质,还影响了mPEG-chol与卵磷脂分子的相互作用。PEG的链越长,与磷脂分子间的作用力越强;mPEG-chol以胆甾基团为锚与磷脂分子发生作用,较长的PEG链反而影响了胆甾基团在磷脂单分子膜中的吸附。

Three mPEG-chols with different molecular weight were synthesized by acyl chloride method.The critical micellar concentrations of three esters have been measured and their pressure-area isotherms on the air/water interface were obtained by using Langmuir balance.The results show that the values of CMC increases with the chain length of PEG increases.The PEG chain lengths also have influence on the surface properties of mPEG-chols on the air/water interface,but also on the interactions between mPEG-chol and phospholipid.