多功能阳离子脂质体跨血脊髓屏障的实验研究

目的探讨异硫氰酸荧光素(FITC)标记阳离子脂质体通过尾静脉注入后,跨越大鼠血脊髓屏障并在局部聚集的情况。方法 30只成年Wistar大鼠随机等分为3组,每组10只,荧光显微镜动态观察脂质体在中枢神经系统(CNS)中靶向聚集与扩散情况,通过组织学观测进一步分析其与CNS细胞的关系。结果相同浓度下(75⁶00μg/m L),TAT-PEG-阳离子脂质体较未经TAT修饰者具更低细胞毒性,且更易被MCF-7细胞摄取;FITC标记TAT-PEG-阳离子脂质体可跨越BSCB并聚集,低倍镜下观察到许多荧光微粒聚集于CNS组织,高倍镜形象地显示出荧光微粒位于神经细胞内。结论经跨膜肽(TAT)、聚乙二醇(PEG)修饰的阳离子脂质体具有良好的生物相容性与靶向定位特性,可跨过BSCB,聚集于CNS细胞中,安全用作药物载体,为中枢神经系统疾病的治疗提供新的途径。

Fitc Loaded Tat-Peg-Modified Liposomes Cross the Blood-Spinal Cord and the Blood-Brain Barriers

Objective To observe the ability of fluorescein isothiocyanate（FITC） loaded transactivating-Wansduction protein（TAT）-polyethylene glycol（PEG）- modified liposomes crossing the blood-spinal cord barrier（BSCB） of rats, then localizing there after injection of caudal veins. Method Thirty rats were divided into three groups. Rats were injected with liposome solution （4.55 mg/kg） via the caudal vein. Using fluorescence microscope and histological methods to analyse. Results At the same concentration（75-600 μg/mL）, TAT-modified liposomes had lower cytotoxicity, and were more easily uptaken by MCF-7 cells than the ones without TAT. We observed that TAT-modified liposomes crossed the BSCB, accumulated in CNS tissue and aggregated into ceils there by microscope. Conclusion TAT-PEG-modified liposomes have the characteristics of bio-compatibility and targeting. They can cross the BSCB acting as a drug carrier and accumulate in CNS tissue for future CNS disease treatment.