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聚乙烯亚胺(polyethyleneimine,PEI)是一种优良的非病毒基因传输载体材料,本文对PEI/DNA复合物粒子的形成机制进行了初步探讨,电泳阻滞实验和紫外测定实验表明,复合物的形成过程中存在着某种过渡状态即珠串样结构,透射电镜的结果提供了相应的例证。此外通过离子强度实验,作者认为在PEI与DNA的复合过程尽管以静电作用为主要作用力,同时也可能存在着其他类型的非静电作用力。PEI/DNA复合物粒子的表面电荷随着N/P的增加逐步增加,但由于DNA的分子质量较大,在N/P为8和12时表面电荷的绝对值较小,容易聚集成葡萄串样聚集体,离子强度实验表明该聚集过程的支配作用力可能是疏水作用力。PEI/DNA复合物在N/P为12时的细胞转染效果与阳性对照组相当,表明聚集的PEI/DNA复合物也具有一定的细胞转染能力。
Polyethylenimine (PEI) is an excellent non-viral gene delivery carrier material. In this paper, the formation mechanism of PEI / DNA composite particles is discussed. The results of electrophoresis retardation assay and ultraviolet measurement show that the complex There is a transitional state during the formation of the bead-like structure, the results of transmission electron microscopy provide a corresponding example. In addition, through the ionic strength test, the authors believe that in the PEI and DNA composite process in spite of electrostatic interaction as the main force, but also may exist other types of non-electrostatic force. The surface charge of PEI / DNA composite particles increased gradually with the increase of N / P. However, due to the larger molecular mass of DNA, the absolute value of surface charge was smaller at N / P of 8 and 12, Sample-like aggregates, ionic strength experiments show that the dominant force of the aggregation process may be hydrophobic force. The transfection efficiency of PEI / DNA complex at N / P of 12 was comparable to that of the positive control group, indicating that the aggregated PEI / DNA complex also had some cell transfection ability.