中文摘要：

本文研究了葡聚糖-精胺阳离子聚合物（DSP）基因载体的性能及其对体外细胞基因的转染效率。氧化葡聚糖与精胺通过还原胺化法反应制得DSP，所得DSP与质粒pEGFP通过静电吸附形成复合物；当DSP／DNA质量比在4：1至20：1，能形成稳定的复合物，复合物粒径为162．6～187．9nm，zeta电位则从＋8．45mV增至＋39．6mV：DSP能有效保护DNA不受核酸酶Ⅰ降解，同时在一定pH范围内载体具有较强的缓冲能力；复合物在质量比为8：1时对SMMC-7721肝癌细胞、BHK-21细胞的转染率分别达到最高，其效果均与Lipofectamine2000相当。该研究表明葡聚糖一精胺阳离子聚合物是一种高效的基因载体。

英文摘要：

This work reports the properties of dextran-spermine polycation （DSP） as a gene vector and its gene transfection efficiency in vitro. Oxidized dextran was reacted by reductive amination with spermine to obtain DSP, the resulted polycation was then incubated with plasmid pEGFP to form polyplexes by electrostatic interactions. DSP formed stable polyplexes when the weight ratio （DSP/DNA） varied from 4：1 to 20： 1. The particle size and zeta potential of polyplexes were in the range of 162.6 - 187.9 nm and increased from ＋ 8.45 mV to ＋ 39.6 mV, respectively. DSP could effectively protect condensed DNA from DNase I degradation, and it showed strong buffering capacity in a certain pH range. The highest yields of transfection efficiency were found to be as high as Lipofectamine 2000 when the polyplexes were transfected to SMMC-7721 and BHK-21 cells at the weight ratio of 8： 1. This research indicates that dextran-spermine polycation is a highly active gene vector in vitro.