卟啉为核的星形聚己内酯嵌段聚乙二醇的合成及释放性能

目的: 克服传统小分子卟啉药物的自淬灭,获得含卟啉药物核的靶向型高分子纳米微粒。方法: 通过开环聚合和酯化反应合成了卟啉为核的聚己内酯嵌段聚乙二醇(SPPCL-b-PEO)共聚物,并利用凝胶渗透色谱、核磁共振谱、红外光谱、紫外可见光谱对其进行了表征。荧光探针法分析SPPCL-b-PEO的光动态效率。透射电镜观察SPPCL-b-PEO的自组装行为。紫外可见光谱分析SPPCL-b-PEO的载药及释放性能。结果: 共聚物中大分子聚己内酯-聚乙二醇(PCL-PEO)骨架能有效延缓卟啉内核的自淬灭。随着共聚物中亲水聚己内酯(PCL)链段质量分数的减小,自组装胶束的形态由球状变为蠕虫状。负载多柔比星的SPPCL-b-PEO纳米微球具有较高的载药量和包封率,且体外释放具有pH依赖性。结论: 潜在的卟啉核以及对pH 5～6的肿瘤组织靶向性使SPPCL-b-PEO满足抗肿瘤光动力治疗和肿瘤靶向给药系统的要求。

Synthesis and release property of porphyrin-cored star-shapedpoly(ε-caprolactone)-block-poly(ethylene glycol)

Objective: In order to overcome the quenching of the traditional micromolecular porphyrin drug,the targeting polymer nanoparticles with porphyrin were obtained. Methods:Porphyrin-cored star-shaped poly(caprolactone)-block-poly(ethylene glycol) copolymers (SPPCL-b-PEO) were synthesized via ring opening polymerization and esterification reaction,and were characterized by gel permeation chromatograph,nuclear magnetic resonance spectrum,fourier transform infrared spectroscopy and ultraviolet visible spectroscopy.The photosensitizing efficiency of SPPCL-b-PEO investigated by fluorescence probe method.The self assembly behavior of SPPCL-b-PEO was investigated by transmission electron microscope.The drug loading and release properties of SPPCL-b-PEO were studied by ultraviolet visible spectroscopy. Results:The polymeric poly(caprolactone)-block-poly(ethylene glycol)(PCL-PEO) skeleton can efficiently prevent self quenching of the central porphyrin in the copolymers.The self assembled aggregates changed from spherical micelles to worm like micelles with decreasing the weight fraction of hydrophilic poly(ethylene glycol)(PEO) block in the copolymers.The Doxorubicin loaded SPPCL b PEO nanospheres possess the high drug content and entrapment efficiency, and exhibit property of pH-induced drug release. Conclusion: SPPCL b PEO will not only provide potential porphyrin core for photodynamic therapy but also improve targeting to pH5～6 tumor tissues for drug delivery.