PLGA微球制备工艺对新城疫病毒稳定性的影响

 目的考察乳酸-羟乙醇酸共聚物(PLGA)微球制备工艺对新城疫病毒的稳定性影响,并寻求合适的保护剂以稳定新城疫病毒的活性。方法　采用复乳-溶剂挥发法制备PLGA微球,并添加不同的保护剂进行考察。紫外分光光度法测定蛋白浓度,利用红血球凝集反应测定病毒效价。结果涡旋、高速离心和搅拌等剪切力时新城疫病毒的活性影响不大;超声时病毒活性产生一定的影响;有机溶剂对病毒活性的影响最大;加保护剂可得到一定的改善。结论制备新城疫病毒的缓释PLGA微球时,宜加冰浴超声,或缩短超声时间,延长超声间隔;选用聚乙二醇6000或羟丙-β环糊精作保护剂可显著稳定病毒活性。如果可避免有机溶剂的使用,将极大地促进新城疫病毒的活性。

Effects of formulation technique of PLGA microspheres on stability of Newcastle disease virus

OBJECTIVE To evaluate the effects of formulation technique of PLGA microspheres on the stability of Newcastle disease virus and to look for a proper protectant to stabilize Newcastle disease virus. METHODS PLGA microspheres with or without additives were prepared by a double-emulsion solvent extraction/evaporation method. The protein concentration was determined by UV spectrophotography. The virus potency was determined by a hemagglutinin test. RESULTS The shearing forces, such as vortex, high speed centrifugation or stirring , had little influences on the activity of Newcastle disease virus. Meanwhile ultrasound had some effects, and organic solvents played the major key. The activity of virus was improved by adding some protectants. CONCLUSION To prepare the better microspheres of PLGA, ultrasound should be performed in the iced bath, and the keeping time should be shorten and the interval time should be lengthen. Polyethylene glycol 6000 or HP-β-cyclodextrin was used as a protectant to stabilize the protein. The activity of Newcastle disease virus will be raised sharply if the organic solvents are avoided.