Obata Yosuke, Suzuki Daisuke, Takeoka Shinji
Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo 169-8555, Japan.
Bioconjug Chem. 2008 May;19(5):1055-63. doi: 10.1021/bc700416u.
We synthesized cationic lipids bearing lysine, histidine, or arginine as a cationic headgroup for use in gene transfer studies. The cationic assemblies formed from lysine- or arginine-type lipids gave unilamellar vesicles (approximately 100 nm diameter), whereas the morphology of the histidine-type lipids was tube-like. The competences of the cationic assemblies were sufficient to form lipoplexes, and the resulting lipoplexes were evaluated in terms of gene expression efficiencies with COS-7 cells. The lysine- or arginine-type lipids exhibited higher gene expression efficiencies than that of Lipofectamine2000, a conventional transgenic reagent, indicating that stable lipoplexes could be prepared between spherical cationic assemblies and plasmid DNA. The gene expression efficiency in relation to the cationic headgroup of the lipids was as follows: lysine > or = arginine > histidine. In addition, gene expression efficiency was enhanced by decreasing the length of the alkyl chain of the hydrophobic moiety. Unlike Lipofectamine2000, no reduction in transfection efficiency in the presence of fetal bovine serum was observed for the lipoplexes formed using synthetic cationic lipids. Moreover, the synthetic cationic lipids revealed remarkably low cytotoxicity compared with Lipofectamine2000. In conclusion, cationic assemblies formed from 1,5-ditetradecyl-N-lysyl-L-glutamate or 1,5-ditetradecyl-N-arginyl-L-glutamate can be used as an effective plasmid DNA delivery system.
我们合成了带有赖氨酸、组氨酸或精氨酸作为阳离子头基的阳离子脂质，用于基因转移研究。由赖氨酸型或精氨酸型脂质形成的阳离子聚集体产生单层囊泡（直径约100nm），而组氨酸型脂质的形态为管状。阳离子聚集体具有足够的能力形成脂质体复合物，并且用COS-7细胞根据基因表达效率对所得的脂质体复合物进行了评估。赖氨酸型或精氨酸型脂质表现出比传统转基因试剂Lipofectamine2000更高的基因表达效率，这表明可以在球形阳离子聚集体和质粒DNA之间制备稳定的脂质体复合物。与脂质阳离子头基相关的基因表达效率如下：赖氨酸≥精氨酸＞组氨酸。此外，通过缩短疏水部分的烷基链长度可提高基因表达效率。与Lipofectamine2000不同，对于使用合成阳离子脂质形成的脂质体复合物，在存在胎牛血清的情况下未观察到转染效率降低。此外，与Lipofectamine2000相比，合成阳离子脂质显示出极低的细胞毒性。总之，由1,5-二十四烷基-N-赖氨酰-L-谷氨酸或1,5-二十四烷基-N-精氨酰-L-谷氨酸形成的阳离子聚集体可作为一种有效的质粒DNA递送系统。
