中文摘要：

目的：构建基于载5-氨基水杨酸（5-ASA）核壳纳米纤维的递药系统,以期达到药物在结肠定位释放的目的。方法：以丙烯酸树脂Eudragit S100为壳层材料、乙基纤维素为核层材料,采用同轴电纺技术制备载5-ASA的核壳纳米纤维,考察制备核壳纳米纤维的主要影响因素;以包封率表征药物的包载情况;扫描电子显微镜（SEM）和透射电子显微镜（TEM）表征纤维的表面形态、直径、核壳结构的形成;以惠迪为参比制剂,在模拟体内胃、小肠、结肠pH环境的释放介质中,评价其释药行为的结肠定位特征。结果：成功制备了载5-ASA核壳纳米纤维,实验条件下初步获得了可用于载药的核壳纳米纤维;纤维呈表面光滑的圆柱形,形成较完全的核壳结构,平均直径为360 nm;5-ASA包载于纤维的核内,包封率为21.0%（n=6）;5-ASA在模拟胃液pH环境中2 h几乎不释放,模拟小肠液pH环境中4 h的累积释放小于20%,而在模拟结肠液pH环境中4 h内可达到100%完全释放,体外结肠定位释药行为优于惠迪。结论：载5-ASA的核壳纳米纤维作为5-ASA的口服结肠定位给药系统（OCDDS）具有可行性。

英文摘要：

Objective： To build oral colon-specific drug delivery system based on core-shell nanofibers for the purpose of the controlled release of a drug in the colon parts.Methods： Coaxial electrospinning technology was used to prepare core-shell nanofibers and drug was added into the core,selecting acrylic resin Eudragit S100 as the shell layer material and choosing ethylcellulose as the core layer material.Investigate the main effect factors during the process of preparing of core-shell nanofibers.Characterize the condition of drug package containing based on encapsulation efficiency.The shape,diameter,and core-shell structure of nanofibers were characterized by TEM and SEM.Making HuiDi as the reference preparation,in a simulated body＇s stomach,small intestine,colon pH environment of release media,evaluating the release behavior of colon characteristics.Results： 5-ASA core-shell nanofibers were prepared successfully,and initially obtained core-shell nano-fibers using for loading drug under experimental conditions;their surface was smooth cylindrical,forming complete core-shell structure,with the average diameter of 360 nm;the encapsulation efficiency was 21.0%（n=6）;5-ASA in the simulated gastric pH environment,there was no drug release within 2 h.In simulated small intestine pH environment,drug cumulative release was less than 20% within 4 h,while in simulated colon pH environment,drug release could achieve completely 100% within 4 h,the vitro colon release behavior was superior to HuiDi.Conclusion： core-shell nanofibers containing 5-ASA as oral 5-ASA colonic drug delivery system（OCDDS） is feasible.