聚乙二醇修饰的钙黄绿素脂质体的制备与评价

Preparation and evaluation of PEGylated calcein-liposome

目的：介绍冷冻融解法结合微滤膜挤出法制备聚乙二醇修饰的钙黄绿素脂质体的工艺。方法：用负染色法对其外观形态进行透射电镜观测，同时运用Zeta电势·粒径分析仪对超声波作用前后钙黄绿素脂质体的粒径分布及其Zeta电势进行检测。对超声波作用下脂质体内包覆的钙黄绿素的释放特性进行了评价。结果：制得的脂质体Zeta电势为负，其直径分布于80--285nm之间，平均直径为150nm。超声波作用后脂质体平均粒径减小，其内所包钙黄绿素快速释放。结论：表明超声波对脂质体内容物的释放具有明显的增强效果。

OBJECTIVE Liposomes as drug delivery systems have attracted particular interests. In this study PEGylated liposome encapsulating calcein was prepared by freezing-thawing and extrusion method. METHODS The morphology of the liposomes was studied by transmission electron microscopy （TEM） with negative staining method. The size distributions and the Zeta potentials of calcein-liposomes were investigated by a Zeta-potential ＆ particle size analyzer, before and after ultrasound treatment. And the release property of encapsulated calcein was also evaluated when the liposomes were exposed to ultrasound. RESULTS The results showed that the liposomes were of multilamellar structure and their size was ranged from 80- 285 nm and had a mean size of 150 nm. The liposome mean size decreased when exposed to ultrasound. CONCLUSION The released rate of encapsulated calcein was d after ultrasonication which indicates the release enhancement of ultrasound.