线型-超支化结构两亲性嵌段聚合物mPEG-b-hPCL的合成、表征、自组装行为及体外释药行为的研究

Synthesis and self-assembled behavior of amphiphilic block coplolymers mPEG-b-hPCL with linear-hyperbranched structure and their application in drug delivery

通过开环聚合、酯化反应等方法制备聚乙二醇-聚己内酯(PEG-b-hPCL)线性-超支化嵌段共聚物,利用核磁(1 H-NMR)、凝胶渗透色谱(GPC)等表征。DSC结果表明超支化PCL的熔程较长;测定临界胶束浓度(CMC),发现随着聚合物中PCL含量增加,胶束CMC下降;在水、甲醇中自组装,发现水中聚集体粒径为300nm左右,大于甲醇中的聚集体;通过透射电镜(TEM)发现水相聚集体为胶束,甲醇相聚集体为纳米颗粒。以吲哚美辛为药物,研究PEG-b-hPCL胶束的载药能力,其载药量在15%左右,包封率在33%左右,36h后累积释放量有所不同,较高PCL含量的胶束的药物释放量较少。

Linear-hyperbranched structure amphiphilic block coplolymers mPEG-b-hPCL were synthesized by ring opening polymerization（ROP）and esterification reaction, characterized by1H-NMR and GPC. DSC results showed that the copolymers had a long melting range between 30 ℃ and 50 ℃. Their critical micelle coneentrations（CMC）were reduced with the increase of PCL content. The eopolymers could formed micelles with hydrodynamic diameters around 300nm in wa- ter but smaller nanoparticles in methanol, confirmed by DLS and TEM. Morover, the mPEG-b-hPCL micelles were capable of encapsulating indometacin with a loading content of 15 w/w% and exhibiting controlled release of up to 40 % loaded drug over a time period of 36 h with higher PCL content.