摘要
目的制备葡激酶突变体(K35R,DGR)的聚乳酸-羟基乙酸(PLGA)微球,使其在包封和释放过程中都能保持活性。方法使用复乳溶剂挥发法制备DGR的PLGA微球,研究了搅拌速度、PLGA浓度、内水相和外水相中的添加剂对蛋白包封率以及微球性质的影响,并进行了DGR微球的体外和体内释放试验。结果2%聚乙烯醇可以有效抑制超声乳化时DGR在水/二氯甲烷界面上的变性,将DGR的活性回收率从16%提高到几乎100%。在外水相中加入NaCl可以显著提高蛋白包封率,同时对微球的粒径分布和表面形态也产生了重要影响。DGR微球的体外释放呈现两个时相,15d释放大约DGR总活性的50%。DGR微球在体内持续释放5d。结论制备的PLGA微球,DGR包封率高,稳定性较好,是DGR的良好载药系统。
Aim To produce poly （lactic-co-glycolic acid ） （PLGA） microspheres, containing a staphylokinase variant （K35R, DGR） with reduced immunogenecity and antiplatelet aggregation activities, which allowed the preservation of protein stability during both particle processing and drug release. Methods DGR-loaded microspheres were fabricated using a double emulsion-solvent evaporation technique. The effects of preparative parameters, such as stirring rate, polymer concentration, and the excipients of both internal and external aqueous phase （W2 ）, on DGR encapsulation efficiency and microsphere characteristics were investigated. In vitro and in vivo release of DGR were conducted and the cause for instability of DGR during release was also investigated. Results Moderate ultrasonic treatment of aqueous DGR/dichloromethane mixtures caused approximately. Eighty four per cent DGR denaturation. However, the activity recovery of DGR almost amounted to 100% when 2% polyvinyl alcohol （PVA） was added into the aqueous phase. It was found that NaCl in the external water phase significantly increased DGR encapsulation efficiency. Furthermore, NaCl in the external water phase played a role in determining size and surface morphology of microsphere. In vitro release test showed a burst release of DGR from microspheres, followed by sustained release of 50% total activity over 15 days. In vivo experiments showed that DGR released from microspheres sustained 5 days. Denaturation of DGR within microspheres might be resulted from acidic microclimate. Conclusion The stability of DGR was effectively protected during microencapsulation and a relatively high encapsulation efficiency of DGR was obtained. PLGA microspheres could be an effective carrier for DGR.
出处
《药学学报》
CAS
CSCD
北大核心
2006年第1期12-18,共7页
Acta Pharmaceutica Sinica
基金
NationalHigh-techResearchDevelopmentProgram(2001AA215291)
关键词
葡激酶
微球
聚乳酸-羟基乙酸
聚乙烯醇
staphylokinase
microspheres
poly （ lactic-co-glycolic acid）
polyvinyl alcohol
