论文部分内容阅读
目的研究聚乙二醇(polyethylene glycol,PEG)化聚酰胺-胺树状大分子(polyamidoamine dendrimer,PAMAM)的理化性质及其作为质粒DNA载体。方法用1H-NMR考察PAMAM-PEG的化学结构;用琼脂糖凝胶电泳法、圆二色谱法和透射电镜法考察复合物的形成;用动态光散射法测定复合物的粒径和zeta电位;用MTT法测定复合物的毒性;用萤光素酶报告基因的表达表征复合物的转染效率。结果结果表明,载体化合物合成成功,PEG修饰度为9%;琼脂糖凝胶电泳结果表明,在N/P比大于2时,复合物能阻滞DNA的电泳;圆二色谱、透射电镜结果表明复合物已经形成,其形态规整,呈球形。随着N/P比的增加,复合物的粒径减小,zeta电位升高;MTT结果表明复合物的细胞毒性小;萤光素酶实验结果表明复合物的转染效率高。结论作为DNA载体,PAMAM-PEG的细胞毒性小、转染效率高,具有很大的研究前景。
Objective To study the physicochemical properties of polyethylene glycol (PEG) -polyamidoamine dendrimer (PAMAM) and its application as a plasmid DNA vector. Methods The chemical structure of PAMAM-PEG was investigated by 1H-NMR. The complex was formed by agarose gel electrophoresis, circular dichroism and transmission electron microscopy. The particle size and zeta potential were determined by dynamic light scattering. The toxicity of the complex was determined by MTT method. The transfection efficiency of the complex was characterized by luciferase reporter gene expression. The results showed that the synthesis of the carrier compound was successful and the degree of PEG modification was 9%. The results of agarose gel electrophoresis showed that the complex could block the electrophoresis of DNA when the N / P ratio was greater than 2. The results of circular dichroism and transmission electron microscopy Complex has been formed, its shape regular, spherical. With the increase of N / P ratio, the particle size of the complex decreased and the zeta potential increased. The cytotoxicity of the complex was low with MTT assay. The luciferase assay indicated that the complex had high transfection efficiency. Conclusion As a DNA vector, PAMAM-PEG has low cytotoxicity and high transfection efficiency and has great research prospects.