PLA-PEG-PLA的微波合成及其磁性载药微球的表征、释药性

摘要

目的 采用微波法合成PLA-PEG-PLA,并以该嵌段共聚物为基质制备ASA/PLA-PEG-PLA载药微球和ASA-Fe3O4/PLA-PEG-PLA载药微球,考察磁性载药微球和非磁性载药微球的药物缓释性能.方法 通过傅立叶变换红外光谱(FT-IR)、核磁(NMR)对微波法合成的PLA-PEG-PLA的微观结构进行了表征分析.采用乳化-溶剂挥发法制备了ASA/PLA-PEG-PLA载药微球,通过正交设计实验优选载药微球的最佳制备条件,在此基础上利用单微乳法制备的Fe3O4纳米粒子制备了ASA-Fe3O4/PLA-PEG-PLA载药微球.通过透射电子显微镜(TEM)、X-射线衍射(XRD)对Fe3O4纳米粒子进行微观结构表征和性能分析.采用傅立叶变换红外光谱(FT-IR),扫描电子显微镜(SEM)对制备的载药微球进行了微观结构的表征和分析.结果 微波法合成的PLA-PEG-PLA是一种三嵌段共聚物.载药微球呈规则球形,表面光滑,粒径分布较均匀,平均粒径约为20μm.体外模拟释药试验表明ASA/PLA-PEG-PLA载药微球和ASA-Fe3O4/PLA-PEG-PLA载药微球24h释药率分别为69.16％和100％.结论 以微波法合成的PLA-PEG-PLA作为药物载体具有明显的缓释作用.ASA-Fe3O4/PLA-PEG-PLA磁性载药微球比ASA/PLA-PEG-PLA非磁性载药微球具有较快的药物释放速率.%Objective PLA-PEG-PLA was synthesized by microwave-assisted polymerization. Drag-loaded microspheres were prepared by using this copolymer as matrix.The drag release properties of the magnetic drug-loaded microsphere and non-magnetic drag-loaded microsphere were observed. Methods The microstructure of synthesized PLA-PEG-PLA was characterized by FT-IR, 'H-NMR. ASA/PLA-PEG-PLA drag-loaded microspheres were prepared by emulsion-solvent evaporation method. The optimum experimental conditions of drag-loaded microspheres were screened by orthogonal experiment. Magnetic ferroferric oxide(Fe3O4) was prepared by water-in-oil microemulsion processing and characterized by TEM and XRD. The microstructure of drag-loaded microspheres was characterized and analyzed by FT-IR, SEM. Results The polymer was synthesized by microwave-assisted method was a ABA type copolymer(PLA-PEG-PLA). The drag-loaded microspheres were of regular sphere and smoothly surface. Their distribution were even and the average diameter was 20um.The drag release of two kinds of drag-loaded microspheres were studied by in-vitro release method. The drag cumulative release ratio of ASA/PLA-PEG-PLA microspheres and ASA-Fe3O4/PLA-PEG-PLA magnetic microspheres were 69.16% and 100%, respectly.Conclusion The PLA-PEG-PLA which was synthesized by microwave-assisted polymerization as a drug carrier has obvious sustained-release property. The drug release rate of ASA-Fe3O4/ PLA-PEG-PLA magnetic drug-loaded microsphere is bigger than that of ASA/PLA-PEG-PLA non-magnetic drug-loaded microsphere.