中文摘要：

目的利用酰化反应合成维生素E-琥珀酰聚赖氨酸接枝共聚物（N-tocopheryl-N＇-succinyl-ε-polylysine,TOS-SA-PLL）作为载体材料,胰岛素作为模型药物,制备p H敏感接枝共聚物囊泡。方法采用核磁共振扫描和红外光谱对接枝共聚物TOS-SA-PLL结构进行表征;利用2,4,6-三硝基苯磺酸法对接枝共聚物的取代度进行测定;利用动态光散射法对囊泡的粒径,多分散性和Zeta电位进行测定;采用超滤离心法测定囊泡的包封率和载药量以及载药囊泡在不同p H条件下的体外释药行为。结果接枝共聚物自组装形成的囊泡平均粒径为165.7-232.3 nm,Zeta电位为-32.2--20.1 m V;载胰岛素共聚物囊泡的包封率最高可达70.15%,载药量（w）为6.55%;体外释放结果表明该接枝共聚物囊泡的释放行为具有p H敏感性的特征。结论 TOS-SA-PLL接枝共聚物囊泡具有p H敏感的特点,其作为水溶性生物大分子药物的载体,在胃肠道传递领域具有较好的应用前景。

英文摘要：

Objective To synthesize the p H-sensitive grafted polymer N-tocopheryl-N-succinyl-ε-polylysine（ TOS-SA-PLL） by the coupling reaction. The vesicles were self-assembled into core-shell carriers by the polymer and insulin was encapsulated as model cargo. Methods The structure of TOS-SA-PLL was confirmed by1H-NM R and FT-IR; the degree of the substitution was determined by 2,4,6-trimitrobenzene sulfonic acid（ TNBS） method; the particle sizes,polydispersity and zeta potentials were measured by dynamic light scattering（ DLS） analysis; the ultra filtration was applied to analyze encapsulation efficiency,drug loading ratio and release in various p H buffers. Results The mean particle sizes and zeta potentials were in the range of 165. 7-232. 3 nm and- 32. 2-- 20. 1 m V,respectively. The encapsulation efficiency and drug loading rate were up to 70. 15% and 6. 55%; the release studies in vitro suggested that the polymer was p H-sensitive and the release of hydrophilic macromolecules encapsulated was dependent on p H. Conclusions The grafted polypeptide based on polymersomes could be a promising candidate for improving the gastrointestinal delivery of hydrophilic macromolecular drugs due to the p H-responsive features.