还原敏感型多柔比星/吲哚美辛共载聚合物胶束的制备及体外抗肿瘤评价

Preparation of Redox-sensitive Polymeric Micelles Co-loaded with Doxorubicin and Indometacin and Evaluation of Antitumor Activity in vitro

本研究以二硫键连接聚乙二醇和非甾体抗炎药吲哚美辛,合成得到还原敏感型两亲性聚合物聚乙二醇-胱胺-吲哚美辛(PCI)。PCI可通过超声法自组装成胶束,负载抗肿瘤模型药多柔比星,得到标题共载聚合物胶束。透射电镜观察结果显示,制得的胶束呈类球形,动态光散射法测得其粒径为(202.0±7.7)nm,多分散性指数为0.260±0.012。载药胶束中多柔比星的包封率和载药率分别为(90.71±3.78)%和(18.82±0.52)%。多柔比星在含有谷胱甘肽(GSH)的磷酸盐缓冲液(PBS)中24 h累积释放率为80%,而在不含GSH的PBS中24 h仅能释放40%左右,提示制品的释药行为具有明显的还原敏感特征。细胞毒性试验结果显示,PCI载体对人肝癌细胞(HepG2细胞)具有有限的杀伤作用,而共载胶束对HepG2细胞具有更好的杀伤效果。然而,相对于游离多柔比星,共载胶束与HepG2细胞共孵育24h后的细胞毒性较弱。细胞摄取试验结果显示HepG2细胞对胶束的摄取作用呈时间依赖性。

Redox-responsive amphiphilic polymer,polyethylene glycol-cystamine-indometacin(PCI),was synthesized by conjugation of polyethylene glycol and the nonsteroidal anti-inflammatory agent indomethacin with disulfide bonds.The self-assembled micelles were prepared from the polymers by ultrasonic method to load the model antineoplastic agent,doxorubicin.Then,the title co-loaded polymeric micelles were obtained.The observation of transmission electron microscopy(TEM)revealed that the micelles were spherical in shape,and the results of dynamic light scattering showed that the average particle size and polydispersity index were(202.0±7.7)nm and 0.260±0.012,respectively.The encapsulation efficiency and drug loading of doxorubicin in the micelles were(90.71±3.78)%and(18.82±0.52)%,respectively.The cumulative release of doxorubicin from the micelles reached 80%in phosphate buffer(PBS)with glutathione(GSH)within 24 h,while in PBS without GSH was only about 40%.It was attributed to the redox-sensitive characteristics of disulfide bonds.The results of cytotoxicity experiments showed that the naked carriers had a certain antitumor effect on human hepatoma cells(HepG2 cells),while the co-loaded micelles presented enhanced antitumor effect on HepG2 cells.However,compared with free doxorubicin,the cytotoxicity of co-loaded micelles was weaker after 24 h co-incubation with HepG2 cells.The results of uptake experiments revealed that the cellular uptake of micelles in HepG2 cells was time-dependent.