基因载体葡聚糖-精胺/DNA复合物的制备及物理性能的研究

Preparation of Dextran-spermine/DNA Complexe,A Gene Vector,and Its Physical Properties

目的:研究非病毒基因载体葡聚糖-精胺阳离子聚合物(DSP)的合成及其与DNA所形成复合物的物理性能。方法:葡聚糖氧化后,通过还原胺法与精胺反应制得DSP,与质粒pEGFP在室温孵育后形成复合物;激光粒度仪测定复合物粒径和Zeta电位;透射电镜观察复合物形态;琼脂糖凝胶电泳观察DSP对DNA的阻滞能力。结果:DSP与DNA在质量比大于4∶1时,能形成稳定的复合物;复合物平均粒径为173.6nm,平均电位为23.2 mV;所形成的复合物呈圆球状;DSP能阻滞DNA不受电场的影响而迁移。结论:葡聚糖-精胺阳离子聚合物是一种制备工艺简单、有应用前景的非病毒基因载体。

Objective： To develop dextran-spermine polycation （DSP） as a non-viral gene vector and to investigate the physical property of DPS-DNA complexes. Methods： Dextran-spermine polycation was synthesized by reductive amination of oxidized dextran with spermine, the resulted polycation was then incubated with DNA to form polyplexes. The particle size and zeta potential were measured by laser particle size analyzer. The physical shape was observed with transmission electronic microscopy. The retardation ability of polyplexes was examined with agarose gel electrophoresis. Result： DSP and DNA could form stable polyplexes when their weight ratio was 4 ： 1 or above. The average particle size and zeta potential of polyplexes were 173.4nm and 23.2mV, respectively. The physical shape of polyplexes was spherical and the DSP could also effectively retard DNA from migration during electrophoresis. Conclusion： DSP is easy of preparation and is a promising non-viral gene vector.