Biophysical and structural characterization of polyethylenimine-mediated siRNA delivery in vitro
Biophysical and structural characterization of polyethylenimine-mediated siRNA delivery in vitro
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DOI：
10.1007/s11095-006-9009-2
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发表时间：
2006-08-01
影响因子：
3.7
通讯作者：
Putnam, David
中科院分区：
文献类型：
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作者：
Grayson, Amy C. Richards;Doody, Anne M.;Putnam, David
目的.本研究的目标如下：1）评估不同聚乙烯亚胺（PEI）结构在模型系统中用于siRNA递送的功效，和2）确定与siRNA递送相关的PEI的生物物理和结构特征。使用由800、25，000（均为支链）和22，000（线性）分子量的PEI在不同N：P比和siRNA浓度下形成的纳米复合物测定生物物理表征（有效直径和ζ电位）、细胞毒性、相对结合亲和力和体外转染效率。以稳定表达荧光素酶的HR 5-CL 11细胞株为模型。在非常窄的条件窗口内观察到成功的siRNA递送，并且仅使用N：P比为6：1和8：1的25，000支化PEI和200 nM siRNA。虽然PEI：siRNA复合物的zeta电位和大小在某些情况下与转染效率相关，但复合物的稳定性也可能影响转染效率。当与其相对成功和易于用于DNA递送相比时，PEI将功能活性siRNA转移至培养物中的细胞的能力令人惊讶地取决于其生物物理和结构特征。
Purpose. The goals of this study were as follows: 1) to evaluate the efficacy of different polyethylenimine (PEI) structures for siRNA delivery in a model system, and 2) to determine the biophysical and structural characteristics of PEI that relate to siRNA delivery.Materials and Methods. Biophysical characterization (effective diameter and zeta potential), cytotoxicities, relative binding affinities and in vitro transfection efficiencies were determined using nanocomplexes formed from PEI's of 800, 25,000, (both branched) and 22,000 (linear) molecular weights at varying N:P ratios and siRNA concentrations. The HR5-CL11 cell line stably expressing luciferase was used as a model system in vitro.Results. Successful siRNA delivery was observed within a very narrow window of conditions, and only with the 25,000 branched PEI at an N:P ratio of 6:1 and 8:1 and with 200 nM siRNA. While the zeta potential and size of PEI:siRNA complexes correlated to transfection efficacy in some cases, complex stability may also affect transfection efficacy.Conclusions. The ability of PEI to transfer functionally active siRNA to cells in culture is surprisingly dependent on its biophysical and structural characteristics when compared to its relative success and ease of use for DNA delivery.