【摘要】 合成和纯化了一个带末端羧基的新的磷脂酰乙醇胺的聚乙二醇衍生物3/4DPPE-PEG3000-COOH。 将这个化合物掺入脂质体后，脂质体在网状内皮系统（肝、脾）的聚集减少，在血中的循环时间明显延长，并表现为一级对数线性消除。脂质体表面的活性羧基可以和其它活性分子反应，这可能为脂质体带来新的功能。更多还原

【Abstract】 A new PE-PEG derivative with an active carboxylic terminal, DPPE-PEG3000-COOH, was synthesized and purified. Its incorporation into small unilamellar liposomes composed of egg phosphatidylcholine and cholesterol conferred the liposomes prolonged circulation in blood and reduced accumulation in the RES, as the traditional methoxy-PEG derivatives of PE displayed. With the active carboxylic groups on the surface, DPPE-PEG3000- COOH liposomes can be linked with some active molecules, which provide liposomes with special functions.更多还原