Okuda Tatsuya, Kidoaki Satoru, Ohsaki Mio, Koyama Yoshiyuki, Yoshikawa Kenichi, Niidome Takuro, Aoyagi Haruhiko
Department of Applied Chemistry, Faculty of Engineering, Nagasaki University, Nagasaki 852-8521, Japan.
Org Biomol Chem. 2003 Apr 21;1(8):1270-3. doi: 10.1039/b212086k.
Dendritic poly(L-lysine) of the 6th generation shows high transfection efficiency into several cultivated cells with low cytotoxicity. In order to understand the mechanism of complex formation with plasmid DNA, the complex was observed using atomic force microscopy. After mixing for 15 min, 1-2 microns assemblies of complexes composed of several small particles (50-200 nm) were observed. At the same time, individual small complexes of 50 to 500 nm were observed on a mica surface. After incubation for 2 h, only the large complexes were found on the mica surface. As a result of further dynamic light scattering analysis and measurement of the transfection efficiency at different time points, the transfection efficiency of KG6 was found to increase with increasing size of the DNA-complexes. This result indicates that large complexes of more than 1 micron are major species that contribute to transfection in vitro.
第六代树枝状聚（L-赖氨酸）对几种培养细胞显示出高转染效率且细胞毒性低。为了了解与质粒DNA形成复合物的机制，使用原子力显微镜观察该复合物。混合15分钟后，观察到由几个小颗粒（50-200纳米）组成的1-2微米的复合物聚集体。同时，在云母表面观察到50至500纳米的单个小复合物。孵育2小时后，在云母表面仅发现大复合物。通过进一步的动态光散射分析和在不同时间点测量转染效率，发现KG6的转染效率随着DNA-复合物尺寸的增加而增加。该结果表明，大于1微米的大复合物是体外转染的主要贡献物种。
