双重介导脑靶向脂质体增强荷载阿霉素的体外血-脑脊液屏障渗透率

Dual-mediated Brain Targeting Liposomes Enhance Blood Barrier Permeability of Loaded Doxorubicin.

目的探讨双重介导脑靶向脂质体(RVGPR9-SSL)作为递送载体对阿霉素(doxorubicin,DOX)血-脑脊液屏障(blood brain barrier,BBB)渗透率的影响,为脑部药物递送提供新的策略。方法利用前期构建的双重介导脑靶向脂质体(RVGPR9-SSL)作为载体包载DOX(DOX@RVGPR9-SSL)。培养脑毛细血管内皮细胞(brain microvascular endothelial cells,BMVEC),在体外构建BBB模型,通过4h渗漏实验、跨膜电阻值(transmembrane resistance value,TEER)测量、扫描透射电镜(scanning transmission electron microscope,SEM)观察细胞间的紧密连接等,鉴定体外BBB模型构建是否成功。在BBB模型构建成功后,利用荧光共振能量转移(fluorescence a resonance energy transfer,FRET),通过激光共聚焦显微镜,考察RVGPR9-SSL体跨越BBB后的完整性。通过对比分析脂质体给药前后,BBB的形态以及TEER值,考察RVGPR9-SSL跨越BBB后对BBB完整性的影响。通过荧光分光光度计,考察DOX@RVGPR9-SSL的BBB渗透率。结果RVGPR9-SSL的包封率为97.25%。构建的BBB模型的TEER值均>200Ω·cm 2,并通过SEM观察到BMVEC细胞排列紧密,存在着明显的紧密连接,说明体外BBB模型成功建立,可用于考察BBB渗透率。DOX@RVGPR9-SSL4h累积BBB渗透率>10%,显著高于游离DOX的4h累积BBB渗透率。给药后BBB与DOX@RVGPR9-SSL均能保持较好的完整性。结论RVGPR9-SSL可以显著提高所包载的DOX的BBB渗透率,并且具有较好的安全性,是非常有前景的脑部药物递送载体。

Objective To study the effect of dual-mediated brain targeting liposomes(RVGPR9-SSL)as delivery vehicles on the blood brain barrier(BBB)permeability of doxorubicin(DOX),providing a new strategy for brain drug delivery.Methods The dual-mediated brain targeting liposomes(RVGPR9-SSL)were prepared by thin film dispersion/leading compound method.And the chemotherapeutic drug DOX was encapsulated in RVGPR9-SSL(DOX@RVGPR9-SSL).Brain microvascular endothelial cells(BMVEC)were cultured and used to construct in vitro BBB models.The BBB model was then evaluated by a 4h leakage test,transmembrane resistance value(TEER)measurement,and tight junctions between cells observed by scanning transmission electron microscope(SEM).After the successful construction of the BBB model,the integrity of RVGPR9-SSL after crossing the BBB was investigated by confocal laser scanning microscopy using fluorescence a resonance energy transfer(FRET)pair.The effect of RVGPR9-SSL administration on BBB integrity was evaluated by comparative analysis of BBB morphology and TEER values before and after liposome administration.The BBB permeability of DOX@RVGPR9-SSL was investigated by fluorescence spectrophotometry.Results The encapsulation efficiency of DOX@RVGPR9-SSL was 97.25%.The TEER values of the constructed BBB model were all greater than 200Ω·cm 2,and it was observed by SEM that the BMVEC cells were closely arranged and there were obvious tight junctions,indicating that the in vitro BBB model was successfully established and could be used for the investigation of BBB permeability.The 4h BBB cumulative permeability of DOX@RVGPR9-SSL was greater than 10%,which was significantly higher than that of free DOX.And both BBB and liposomes maintained good integrity after administration.Conclusion RVGPR9-SSL can significantly improve the BBB permeability of DOX,indicating that it is a very promising brain drug delivery vehicle.