酸敏性葡聚糖纳米凝胶的制备与释药性质考察

目的制备具有酸敏特性的聚（甲基丙烯酸缩水甘油酯修饰葡聚糖,dex GMA）/（丙烯酸,AAc）纳米凝胶,研究其降解和释药性质。方法乳液聚合法制备poly(dex GMA/AAc)纳米凝胶,测定不同pH值下的粒度分布,以红霉素（EM）为药物模型,动态透析法测定纳米凝胶在不同pH值下的释药性质。结果poly(dex GMA/AAc)纳米凝胶的平均粒径约为100 nm,包裹率、载药率分别为90.7%和1.06%。在无酶人工胃液 (SGF) 2 h纳米凝胶的药物累积释放率分别为7.0%,之后在无酶人工肠液(SIF)里4 h 内增加到37.0%。结论poly(dex GMA/AAc)纳米凝胶具有酸敏特性,在SGF里释放少量药物,在SIF里凝胶溶胀、降解,药物释放量明显增大。poly(dex GMA/AAc)纳米凝胶是潜在的结肠靶向载体。

Preparation and Drug Release Characteristics of the pH-sensitive Dextran Hydrogel Nanoparticles

Objective To prepare the pH-sensitive glycidyl methacrylate derivatized dextran(dex-GMA)/acrylic acid(AAc) poly(dex-GMA/AAc) nanoparticles,and study their properties such as drug release and degradation. Methods The poly(dex-GMA/AAc) nanoparticles were prepared by emulsion polymerization.Under different pH,the particle size distribution and drug release of poly(dex-GMA/AAc) nanoparticles were determined by dynamic dialysis methods with erythromycin as a drug model. Results The mean diameter of poly(dex-GMA/AAc) nanoparticles was about 100 nm,the drug loading rate and encapsulation efficiency were 90.7%,and 1.06%,respectively.In the artificial gastric fluid without enzymes(SGF),the cumulative drug release ratio was 7.0% within 2 h,afterwards reached to 37.0% within 4 h in the artificial intestinal fluid(SIF) without enzymes. Conclusion The poly(dex-GMA/AAc) nanoparticles were pH-sensitive,which released EM slightly in SGF,whereas released considerably more in SIF by swelling and degradating.It is suggested that the poly(dex-GMA/AAc) nanoparticle would be a potential colon-target carrier.