Kang Ji Hee, Jang Woo Young, Ko Young Tag
College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, 191 Hambakmoe-ro, Yeonsu-gu, Incheon, South Korea, 21936.
Pharm Res. 2017 Apr;34(4):704-717. doi: 10.1007/s11095-017-2097-3. Epub 2017 Jan 11.
Liposomes have been developed as versatile nanocarriers for various pharmacological agents. The effect of surface charges on the cellular uptake of the liposomes has been studied by various methods using mainly fixed cells with inevitable limitations. Live cell imaging has been proposed as an alternative methods to overcome the limitations of the fixed cell-based analysis. In this study, we aimed to investigate the effects of surface charges on cellular association and internalization of the liposomes using live cell imaging.
We studied the cellular association and internalization of liposomes with different surface charge using laser scanning confocal microscopy (LSCM) equipped with live cell chamber system. Flow cytometry was also carried out using flow cytometer (FACS) for comparison.
All of the cationic, neutral and anionic liposomes showed time-dependent cellular uptake through specific endocytic pathways. In glioblastoma U87MG cells, the cationic and anionic liposomes were mainly taken up via macropinocytosis, while the neutral liposomes mainly via caveolae-mediated endocytosis. In fibroblast NIH/3T3 cells, all of the three liposomes entered into the cell via clathrin-mediated endocytosis.
This study provides a better understanding on the cellular uptake mechanisms of the liposomes, which could contribute significantly to development of liposome-based drug delivery systems.
脂质体已被开发为多种药理活性剂的通用纳米载体。表面电荷对脂质体细胞摄取的影响已通过各种方法进行研究，这些方法主要使用固定细胞，存在不可避免的局限性。活细胞成像已被提议作为克服基于固定细胞分析局限性的替代方法。在本研究中，我们旨在使用活细胞成像研究表面电荷对脂质体细胞结合和内化的影响。
我们使用配备活细胞室系统的激光扫描共聚焦显微镜（LSCM）研究了具有不同表面电荷的脂质体的细胞结合和内化。还使用流式细胞仪（FACS）进行流式细胞术以作比较。
所有阳离子、中性和阴离子脂质体均通过特定的内吞途径表现出时间依赖性的细胞摄取。在胶质母细胞瘤U87MG细胞中，阳离子和阴离子脂质体主要通过巨胞饮作用摄取，而中性脂质体主要通过小窝介导的内吞作用摄取。在成纤维细胞NIH/3T3细胞中，所有三种脂质体均通过网格蛋白介导的内吞作用进入细胞。
本研究为脂质体的细胞摄取机制提供了更好的理解，这可能对基于脂质体的药物递送系统的开发有显著贡献。
