DSPE-PEG,Tween80和Brij35对伊文思蓝脂质体包封率和体内分布的影响

目的寻找与DSPE．PEG功能相似的表面活性剂，以增加脂质体的稳定性，改善其体内分布，提高靶向性。方法制备了伊文思蓝脂质体，考察了胆固醇与磷脂的比例对伊文思蓝脂质体包封率的影响；比较了用DSPE-PEG、Tween80和Brij35修饰后的伊文思蓝脂质体包封率和在大鼠体内分布状况的变化。结果伊文思蓝脂质体的包封率最高为25．30％。用DSPE-PEG、Tween80和Brij35修饰后使伊文思蓝脂质体的包封率略有下降，但差别不显著；体内分布实验结果显示：修饰后的脂质体在肝、脾和肾中伊文思蓝的浓度均有不同程度的降低，脑中伊文思蓝的浓度有所提高，而且以Tween80修饰组最显著。结论DSPE-PEG、Trween80和Brij35对伊文思蓝脂质体的包封率影响较小。Brij35对伊文思蓝脂质体的作用与DSPE-PEG相似，能提高脂质体逃避网状内皮系统吞噬的能力；Tween80主要能增加伊文思蓝脂质体在大鼠脑组织中的分布，为脑靶向脂质体的研究提供了有益信息。

Comparative Efficacy and Distribution of Evans Blue Liposome Modified with DSPE-PEG, Tween80, and Brij35

Aim To improve the stability and optimize the tissue distribution of Evans blue liposome in rats, some surfactants such as DSPE PEG, Tween80, and Brij35 were used to modify the Evans blue liposome. Methods The Evans blue liposome was prepared by the reverse phase evaporation method. The effect of cholesterol on the encapsulation percentage of Evans blue was studied. The effects of DSPE PEG, Tween80, and Brij35 on the encapsulation percentage and tissue distribution of Evans blue liposome in the rat were determined. Results The top encapsulation percentage of Evans blue liposome is 25 30%. After modification by DSPE PEG, Tween80, and Brij35, the encapsulation percentages decreased slightly, but not significantly. After modification, the Evans blue concentrations deceased in the liver, spleen, lung and kidney, but increased in the brain, especially in the EB L Tween80 group. Conclusion DSPE PEG, Tween80, and Brij35 have slight effect on the encapsulation percentage of Evans blue liposome. The effect of Brij35 on the distribution of Evans blue liposome is similar to that of DSPE PEG because they both is prevent the reticuloendothelial system (RES) from clearing liposome. The Evans blue concentration in the brain is greatly improved when Tween80 is used to modify the EB liposome, which is good information for preparing liposome targeting the brain.