硫酸软骨素酶ABC-聚乳酸-聚乙醇酸共聚物缓释微球的制备及其体外性质

Preparation and in vitro properties of controlled release poly(lactic-co-glycolic acid) microspheres incorporating chondroitinase ABC

背景:硫酸软骨素酶ABC能够分解脊髓损伤局部持续产生的硫酸软骨素蛋白多糖,从而促进轴突的生长,但该酶性质不稳定,需要多次局部用药。目的:制备硫酸软骨素酶ABC-聚乳酸-聚乙醇酸共聚物缓释微球,观察其体外释药特性。设计、时间及地点:重复测量设计,于2006-03/2007-01在中国科学院成都有机所和四川大学华西医学中心药理实验室完成。材料:聚乳酸-聚乙醇酸共聚物、硫酸软骨素酶ABC、CH2Cl2、硫酸软骨素B。方法:复乳法制备硫酸软骨素酶ABC缓释微球,并以生理盐水为体外释药介质。主要观察指标:扫描电镜下观察硫酸软骨素酶ABC缓释微球的形态。应用Malvern激光粒度分布测试仪测定其粒径分布并自动计算微球的平均粒径和径距。采用酶解分光光度测定硫酸软骨素酶ABC含量,并计算载药量与包封率。于0.5,1,1.5,2,3,4,6,8,10,12,14,16,18,21d取样,绘制体外释药曲线。结果:硫酸软骨素酶ABC缓释微球形态均匀,其平均粒径5.538μm,径距1.479,呈正态分布。平均载药量(15.55±0.90)×10-3%,平均包封率(53.88±1.45)%,硫酸软骨素酶ABC微球在3周内的体外累积释药分数为0.8514,释药平稳,其最佳体外释药拟合方程为Weibull方程:lnln(1/1-Y)=0.7396lnX-1.617,R2=0.9933。结论:所制备的硫酸软骨素酶ABC微球形态均匀,粒径分布窄,再分散性好,3周内能维持有效的药物浓度。

BACKGROUND： Chondroitinase ABC promotes the outgrowth of axons by disruption of chondroitin sulphate proteoglycans, which is expressed in the local site of spinal cord injury. It is necessary to multiple administrations or controlled release of chondroitinase for its unstability. OBJECTIVE： To prepare the chondroitinase ABC microspheres with controlled release poly（lactic-co-glycolic acid） （PLGA）, and observe the general properties in vitro. DESIGN, TIME AND SETTING： Repeated measurement trials were performed in Chengdu Organic Chemicals Co., Ltd., Chinese Academy of Sciences and Pharmacology Laboratories of West China Center of Medical Science of Sichuan University from March 2006 to January 2007. MATERIALS： PLGA, chondroitinase ABC. CH2Cl2 and condroitin B. METHODS： Chondroitinase ABC-PLGA microspheres were prepared with double emulsion methods. The salt solutions were taken as the medium of the drug release in vitro. MAIN OUTCOME MEASURES： The morphous of chondroitinase ABC PLGA microspheres was observed under scanning electron microscope, the particle diameter distributions were measured using Malvern laser particle size analyzer, the drug loading rate and encapsulation rate of the microspheres were detected using enzymatic hydrolysis spectrophotometry, and the drug release curve in vitro was drawn at days 0.5, 1, 1.5, 2. 3, 4, 6, 8, 10, 12, 14, 16, 18 and 21. RESULTS： The morphology and the particle size distribution of the chondroitinase ABC microspheres were good, with a mean diameter of 5.538 μ m and a span of 1.479. The average drug loading was （15.55±0.90）%, the average drug encapsulation rate was （53.88±1.45）%; The cumulative drug release ratio was 0.851 4 within 3 weeks, and with a stable drug release properties and fit for the Weibull equations： lnln（ 1/1 - Y）5=0.739 6lnX-1.617, R^2=0.993 3. CONCLUSION： The chondroitinase ABC microspheres exhibit well-distributed morphology, narrow particle size distribution and good redispersibility, they can maintain an therapeutic concentration within 3 weeks.