中文摘要：

通过扫描电镜和原子力显微镜实验表明O,O-双十二酰化壳聚糖可形成一种新型的自组装纳米药用泡囊，其粒径主要分布在100～200nm。考察了3种不同酰化取代度的O,O-双十二酰化壳聚糖自组装泡囊的体外药物（维生素B12）释放行为。结果表明自组装泡囊的药物释放速率随酰化取代度的增大而降低。同时在自组装泡囊的制备过程中加入胆固醇，能引起自组装泡囊的药物释放速率增大。壳聚糖基材料的酰化取代度对自组装药用泡囊的载药量的影响较小，但对自组装药用泡囊的药物包封率有显著的影响。酰化取代度为1．3、1．4和1．7的三种O，O-双十二酰化壳聚糖自组装泡囊药物包封率分别为29．52％、31．55％和39．88％。

英文摘要：

The SEM and AFM experiments showed that O, O-dilauroyl chitosan could form a new kind of self-assembled vesicles for drug delivery and the diameter of the vesicles was mainly 100-200nm. The effects of degree of acylation of chitosan and addition of lecithin on the behavior of O, O-dilauroyl chitosan self-assembled vesicles were studied in this work. The experimental results showed that the rate of drug-release of the vesicles decreased with increasing degree of acylation, and the rate could be increased with the addition of lecithin. The degree of acylation of chitosan had hardly any effect on the drug loading capacity of O, O-dilauroyl chitosan self-assembled vesicles, but obviously affected the drug encapsulation efficiency. The drug encapsulation efficiencies of three kinds of the vesicles made from different acylated chitosans were 29.52%, 31.55% and39.88% for degree of acylation 1.3, 1.4 and 1.7 respectively.