包载 rhBMP-2和 SDF-1的双层纳米微球的构建及体外释药研究

摘要

目的：构建搭载基质细胞衍生因子1（SDF-1）和人骨形态发生蛋白2（rhBMP-2）的双层纳米微球缓释系统，研究其体外释药特性。方法：用“乳化-溶剂挥发法”制备聚乳酸／壳聚糖（PLA ／CS）双层纳米微球，通过正交试验获得最佳制备参数；动态光散射法测定纳米微球的粒径，电镜观察纳米微球的形态；在乳化过程中将 rhBMP-2和 SDF-1依次加入纳米微球中，计算其包封率和载药量，透析袋扩散法检测其体外缓释效果。结果：制备的双层纳米微球外形圆整，表面光滑，平均粒径为（542．33±14．38）nm，微球之间无粘连。rhBMP-2包封率为（82．41±1．05）％，载药量为（24．67±0．43）ng／mg；SDF-1包封率为（75．58±0．84）％，载药量为（22．63±0．41）ng／mg。药物释放持续至少30 d，呈“双相释放”。第30天时累计释放的 rhBMP-2和 SDF-1分别为72．85％和91．01％。结论：成功制备了包裹 SDF-1和 rhBMP-2的双层载药微球，形态良好，包封率较高，体外缓释效果较好。%Objective:To construct double-layered controlled release system containing SDF-1 and rhBMP-2 molecules and to study the release profile of the system in vitro.Methods:The polylactic acid/chitosan(PLA/CS)nanoparticles were prepared with “emulsification-solution evaporation method”,the preparation parameters were determined by orthogonal test design.The particle size was observed by nanoparticle size analyzer,the morphology of the nanoparticles was observed with electron microscope.Then rhBMP-2 and SDF-1 were loaded into the nanoparticles in the process of emulsification,the loading efficiency and encapsulation efficiency were calculated and in vitro release was observed.Results:The double-layer nanoparticles showed spherical geometry,smooth surface and complete separation. The average particle size of the nanoparticles was (542.33 ±14.38)nm;The drug loading and incorporation efficiency of rhBMP-2 were (82.41 ±1.05)% and (24.67 ±0.43)ng/mg,those of rhBMP-2 were (75.58 ±0.84)% and (22.63 ±0.41)ng/mg,respectively. The release time of the drug from the system sustained over at least 30 days,the release profile of both drugs showed “biphasic release”. The cumulative release rate of SDF-1 and rhBMP-2 was 72.85% and 91.01% in 30 days respectively.Conclusion:The SDF-1 and rh-BMP-2 loaded PLA/CS nanoparticles have excellent morphology,high entrapment and good sustained-release in vitro.