Revisit complexation between DNA and polyethylenimine - Effect of uncomplexed chains free in the solution mixture on gene transfection.
Revisit complexation between DNA and polyethylenimine - Effect of uncomplexed chains free in the solution mixture on gene transfection.
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DOI：
10.1016/j.jconrel.2010.10.028
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发表时间：
2011-10
期刊：
影响因子：
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通讯作者：
Y. Yue;F. Jin;Rui Deng;J. Cai;Yangchao Chen;Marie C. M. Lin;H. Kung;Chi Wu
中科院分区：
文献类型：
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作者：
Y. Yue;F. Jin;Rui Deng;J. Cai;Yangchao Chen;Marie C. M. Lin;H. Kung;Chi Wu
我们用激光光散射法和凝胶电泳法研究了阴离子聚乙烯亚胺与阳离子聚乙烯亚胺在水和磷酸盐缓冲溶液中的络合反应，结果表明，当N：P摩尔比为3时，几乎所有的DNA链都与PEI络合形成复合体，但只有当N：P≥10时，PEI/DNA复合体才具有较高的基因体外转染率。综合这两个事实，我们不仅得出结论，这7条额外的PEI链在溶液中是游离的，但也证实，正是这些游离的PEI链实质上促进了基因转染，无论它们是在给药效率低得多的PEI/DNA多重体(N：P=3)之前或之后几个小时施加的。流式细胞仪测定的摄取动力学表明，游离PEI的加入导致多聚体更快、更有效地内化，但这些游离的PEI链主要促进随后的细胞内转运。相比之下，结合的PEI链主要在DNA的缩合和保护中发挥作用，导致了非病毒载体的开发有不同的思路。
Our revisit of the complexation between anionic DNA and cationic polyethylenimine (PEI) in both water and phosphate buffered saline (PBS) by using a combination of laser light scattering (LLS) and gel electrophoresis confirms that nearly all the DNA chains are complexed with PEI to form polyplexes when the molar ratio of nitrogen from PEI to phosphate from DNA (N:P) reaches ~3, but the PEI/DNA polyplexes have a high in-vitro gene transfection efficiency only when N:P≥10. Putting these two facts together, we not only conclude that this extra 7 portions of PEI chains are free in the solution mixture, but also confirmed that it is these free PEI chains that substantially promote the gene transfection no matter whether they are applied hours before or after the administration of the much less effective PEI/DNA polyplexes (N:P=3). The uptake kinetics measured by flow cytometry shows that the addition of free PEI leads to a faster and more efficient cellular internalization of polyplexes, but these free PEI chains mainly contribute to the subsequent intracellular trafficking. In contrast, the bound PEI chains mainly play a role in the DNA condensation and protection, leading to a different thinking in the development of non-viral vectors.