包裹破伤风类毒素蛋白的聚乳酸及聚乳酸/聚乙醇酸共聚微球的制备和体外释放特性

 目的探索包裹破伤风类毒素蛋白（TT）的聚乳酸(PLA）及聚乳酸/聚乙醇酸(PLG)共聚微球的制备及其体外释放特性。方法采用溶剂蒸发技术,先以一种小分子量生物染料 伊文思蓝为包裹物模型，通过显微镜观察和比色分析探索微球的制备特性和最佳条件。在此基础上制备包裹TT的PLA和 PLG微球。结果微球的制备过程中存在着内水相蛋白朝外水相的流失，当聚合物浓度加大到25%～30%时可使蛋白流失大大减少。包裹蛋白在微球中的分布与微球粒径的重量分布成正相关关系；随着微球粒径的增大，微球所载蛋白的体外释放高峰期延迟。结论通过本模型条件可制备外观高质量的微球，并可通过制备不同粒径大小的微球来控制包裹蛋白在体外和体内的释放高峰期。

Preparative techniques and release properties of PLA and PLG microspheres containing tetanus toxoid protein

OBJECTIVE To investigate the preparation and release properties of poly lactid acid(PLA) and poly lactid co glycolide acid (PLG) microspheres (MS) containing tetanus toxoid (TT) protein.METHOD The preparation property and optimum techniques of PLAMS were investigated by microscope and colorimetry using Even's blue, a low molecular weight bio dye as a model encapulating material.According to the optimum techniques,the microspheres containing TT protein were prepared.RESULT During the preparation of microspheres containing TT protein,the loss of TT protein from internal aqueous phase to external aqueous phase occurred and the loss of TT decreased when the concentration of polymer in dichlormethane increased to 25%～30%.The distribution of encapulated TT protein in microspheres was relevant with the weight distribution of different size of microspheres.In vitro,the peak release time of encapulated TT protein was delayed when the diameter of microspheres increased. CONCLUSION The TT protein loading PLA and PLG microspheres with a smooth and non porous surface was prepared by optimum techniques.The different size of microspheres containing TT protein can also be prepared for the need of controlled peak release time of encapulated TT protein in vitro and in vivo.