本文利用阴离子型界面活性剂十二烷基硫酸钠(SDS)和阳离子型界面活性剂十二烷基三甲基溴化铵(DTAB)形成DTAB/SDS离子对双亲分子, 通过制膜、超声振荡与挤压等程序制备出阴阳离子液胞, 并利用动态光散射技术探讨不同比例的胆固醇添加对液胞稳定性的影响。研究结果表明, 添加胆固醇可以明显增强DTAB/SDS阴阳离子液胞的物理稳定性; 但胆固醇添加量小于35mol%时并不足以使系统内的阴阳离子界面活性剂全部转换为稳定的液胞而有结晶物产生; 当胆固醇添加量更少(10mol%)时能稳定存在的液胞数量更少, 所以计数率明显下降。由这些结果可以推论胆固醇与阴阳离子界面活性剂在液胞的双层膜中是以固定比例排列存在, 从而可以维持液胞的稳定性, 因此胆固醇添加量较高时液胞稳定性较佳。

A ion pair amphiphile was made of an anionic surfactant, sodium dodecylsulfate (SDS), and cationic surfactant, dodecyltrimethylammonium bromide (DTAB) and catanionic vesicles were then prepared from the ion pair amphiphiles with the processes of film preparation, sonication and extrusion, and the influence of the added cholesterol on the stability of the vesicles was investigated in this paper. The results showed that cholesterol addition can improve greatly the stability of DTAB/SDS catanionic vesicles. Crystal substances are produced when the addition amount of cholesterol is less than 35mol%, because the ion pair amphiphiles being not transformed into the stable catanionic vesicles completely. The number of stable vesicles is much less for addition amount of 10mol% and it leads to the count rate falling obviously. It can be obtained form above discusses that cholesterol and ion pair amphiphile are existed in the double membrane of vesicle according to the fixed ratio, which can hold the stability of vesicle. More the cholesterol adding, more stable the DTAB/SDS catanionic vesicle is.