Wang Bing, Zhao Rui-Mo, Zhang Ji, Liu Yan-Hong, Huang Zheng, Yu Qing-Ying, Yu Xiao-Qi
Key Laboratory of Green Chemistry and Technology (Ministry of Education), College of Chemistry, Sichuan University, Chengdu 610064, PR China.
Key Laboratory of Green Chemistry and Technology (Ministry of Education), College of Chemistry, Sichuan University, Chengdu 610064, PR China.
Eur J Med Chem. 2017 Aug 18;136:585-595. doi: 10.1016/j.ejmech.2017.05.038. Epub 2017 May 17.
Although numerous cationic lipids have been developed as non-viral gene vectors, the structure-activity relationship (SAR) of these materials remains unclear and needs further investigation. In this work, a series of lysine-derived cationic lipids containing linkages with different rigidity were designed and synthesized. SAR studies showed that lipids with rigid aromatic linkage could promote the formation of tight liposomes and enhance DNA condensation, which is essential for the gene delivery process. These lipids could give much higher transfection efficiency than those containing more flexible aliphatic linkage in various cell lines. Moreover, the rigid aromatic linkage also affords the material higher serum tolerance ability. Flow cytometry assay revealed that the target lipids have good cellular uptake, while confocal microscopy observation showed weaker endosome escape than Lipofectamine 2000. To solve such problem and further increase the transfection efficiency, some lysosomotropic reagents were used to improve the endosome escape of lipoplex. As expected, higher transfection efficiency than Lipofectamine 2000 could be obtained via this strategy. Cytotoxicity assay showed that these lipids have lower toxicity in various cell lines than Lipofectamine 2000, suggesting their potential for further application. This work demonstrates that a rigid aromatic linkage might distinctly improve the gene transfection abilities of cationic lipids and affords information to construct safe and efficient gene vector towards practical application.
尽管已经开发出许多阳离子脂质作为非病毒基因载体，但这些材料的构效关系（SAR）仍不清楚，需要进一步研究。在这项工作中，设计并合成了一系列含有不同刚性连接键的赖氨酸衍生阳离子脂质。构效关系研究表明，具有刚性芳香族连接键的脂质可以促进紧密脂质体的形成并增强DNA凝聚，这对于基因递送过程至关重要。在各种细胞系中，这些脂质比含有更灵活脂肪族连接键的脂质具有更高的转染效率。此外，刚性芳香族连接键还赋予材料更高的血清耐受能力。流式细胞术分析表明，目标脂质具有良好的细胞摄取能力，而共聚焦显微镜观察显示其从内涵体逃逸的能力比Lipofectamine 2000弱。为了解决这个问题并进一步提高转染效率，使用了一些溶酶体促渗剂来改善脂质体复合物从内涵体的逃逸。正如预期的那样，通过这种策略可以获得比Lipofectamine 2000更高的转染效率。细胞毒性分析表明，这些脂质在各种细胞系中的毒性比Lipofectamine 2000低，表明它们具有进一步应用的潜力。这项工作表明，刚性芳香族连接键可能会显著提高阳离子脂质的基因转染能力，并为构建安全有效的基因载体以实现实际应用提供了信息。
