白介素13介导的卡莫司汀聚合物胶束靶向性治疗脑胶质瘤研究

Research of Interleukin-13 Modified BCNU Micelles in Targeted Therapy for Glioma

目的:以白介素13(IL-13)作为肿瘤主动靶向配体,构建能够穿透血脑屏障的胶束递药系统,延长卡莫司汀(carmustine,BCNU)在脑部消除半衰期,以实现其增效减毒。方法:以二硬脂酰基磷脂酰乙醇胺-聚乙二醇(DSPE-PEG)/二氨基聚乙二醇硬脂酰基磷脂酰乙醇胺(DSPE-PEG-NH2)为载体,包载抗肿瘤药物BCNU,采用薄膜水合法制备载药胶束,再通过EDC/NHS缩合法将IL-13锚定在聚合物胶束的表面,制备具有主动脑靶向能力的胶束载药系统(BCNU-loaded IL-13 modified micelle,BCNU-M-IL13)。通过考察胶束粒径、Zeta电位、形态学、包封率、体外累计释放等指标,评价胶束的药剂学性能;通过MTT法考察载药胶束对人源脑胶质瘤BT325细胞的抗增殖作用;同时通过考察静脉注射载药胶束后脑组织匀浆的药物半衰期,评价其脑部靶向及滞留性能。结果:BCNU-MIL13粒径为(86.6±1.2)nm,表面电位为(-18.6±2.1)m V,透射电镜结果显示胶束外观圆整,粒径分布窄,BCNU载药量为(3.8±0.1)%,包封率为(93.5±2.7)%;其48 h累计释放率为(48.6±2.7)%;体外抗肿瘤活性实验表明BCNU-M-IL13对BT325的IC50为(44.9±0.5)μmol·L-1;脑组织匀浆的半衰期为1.7 h。结论:本研究首次制备得到BCNU-M-IL13,制备工艺简单,并对其制剂学性质进行了考察,结果表明其制剂学性能优异,且与游离药物相比,体外抗肿瘤活性明显增强,脑内半衰期得到显著改善。

Objective： To prepare BCNU-loaded micelles modified with interleukin-13 （IL 13） as gliomas-targetingligand that can penetrate the blood-brain barrier and raise the concentration of BCNU in brain, and enhancethe anti-tumor activity. Methods： BCNU-loaded micelles （BCNU-M） were prepared by film hydration withDSPE-PEG and then IL 13 was anchored on the particle surface by EDC/NHS aqueous phase condensation in orderto build active glioma-targeting BCNU micelles （BCNU-M-IL13）. Preparation conditions were screened andoptimized based on particle size, Zeta potential and encapsulation efficiency of the micelles. Pharmaceutic performanceswere investigated for particle size, Zeta potential, morphology, encapsulation efficiency, loading-rate and invitro release. An MTT method was used to compare the toxicities of BCNU, BCNU-M and BCNU-M-IL 13 onBT325 cells. The half-lives of BCNU, BCNU-M and BCNU-M-IL 13 in brain were examined after intravenous injection.Results： The particle size of BCNU-M-IL13 was （86.6±1.2）nm, the surface potential was （-18.6±2.1）mV,transmission electron microscopy showed that the micelles were round with narrow particle size distribution. Theencapsulation efficiency was （93.5±2.7）%; the drug loading rate was （3.8±0.1）%; and the cumulative release rate ofB C N U fo r4 8 h w a s （46.8±3.9）%.IC5 0 ofBCN U -M-IL1 3 fo rB T 325 w a s （44.9±0.5）pmol.L-1; thehalf-life o fB C -NU in rat brain after BCNU-M-IL13 injection was 1.7 h. Conclusion： Interleukin-13 modified BCNU micellesprepared in this study are simple in production with excellent pharmaceutical properties. They stay longer in brainwith stronger anti-tumor effects.