转铁蛋白修饰蛇床子素长循环脂质体的处方筛选与体外跨血脑屏障研究

Study of Formulation Optimization and Crossing the Blood-Brain Barrier in Vitro of Transferrin Modified Osthole Long-Circulating Liposomes

目的优选转铁蛋白(Tf)修饰蛇床子素(Ost)长循环脂质体(Tf-Ost-Lip)的处方,并考察其体外跨越血脑屏障的能力。方法利用薄膜分散法制备Tf-Ost-Lip,以Ost包封率为考察指标,采用星点设计-响应面法优化卵磷脂(EPC)浓度(mg/mL),EPC与胆固醇(Chol)质量比(mg/mg),EPC与Ost质量比(mg/mg),测定各脂质体中Ost的包封率。构建血脑屏障体外模型,比较蛇床子素长循环脂质体(Ost-Lip)跨越血脑屏障的能力。结果通过星点设计-效应面法,确定了该脂质体的最优处方为EPC浓度为5.12 mg/mL,EPC与Chol质量比为4.89(mg/mg),EPC与Ost质量比为17.67(mg/mg)。按照优选出的最佳处方,以EPC、Chol、DSPE-PEG_(2000)及Tf-DSPE-PEG_(2000)为膜材制备的Tf-Ost-Lip的包封率为91%以上。体外细胞摄取实验结果表明,hCMEC/D3细胞对Tf-Ost-Lip的摄取效率与Ost-Lip相比显著提高。结论成功优化适用于制备Ost-Lip的处方,Ost-Lip经过Tf修饰后,其跨血脑屏障的能力显著增强,被认为是一种潜在的高效的脑靶向纳米给药系统。

Objective To optimize the formulation of transferrin(Tf)modified Osthole(Ost)long circulating liposomes(Tf-Ost-Lip),and investigate its ability to cross the blood-brain barrier in vitro.Methods Tf-Ost-Lip was prepared by the thin film dispersion method,and the encapsulation rate of Ost was used as the indicator.The central composite design-response surface method was used to optimize the lecithin(EPC)concentration(mg/mL).The mass ratio of EPC to cholesterol(Chol)(mg/mg)and the mass ratio of EPC to Ost(mg/mg)were used to determine the encapsulation efficiency of Ost in liposomes.An in vitro model of the blood-brain barrier was constructed to compare the ability of osthole long-circulating liposomes(Ost-Lip)to cross the blood-brain barrier.Results The optimal formulation of the liposome was determined to be EPC concentration of 5.12 mg/mL,EPC to Chol mass ratio of 4.89 mg/mg,EPC to Ost mass ratio of 17.67 mg/mg.According to the optimal prescription,the encapsulation efficiency of Tf-Ost-Lip prepared with EPC,Chol,DSPE-PEG_(2000) and Tf-DSPE-PEG_(2000) as membrane materials was over 91%.The in vitro cell uptake results showed that the uptake efficiency of Tf-Ost-Lip by hCMEC/D3 cells was significantly higher than that of Ost-Lip.Conclusion The prescription suitable for the preparation of Ost-Lip was successfully optimized.After Ost-Lip was modified with Tf,its ability to cross the blood-brain barrier was significantly enhanced,and it was considered as a potential and efficient brain-targeted nano-drug system.