一种可降解的阳离子聚合物基因转染试剂

A Degradable Cationic Polymer Gene Transfection Reagent

目的:合成一种高效、低毒的新型阳离子聚合物载体。方法:以低分子量的聚乙烯亚胺(PEI)为阳离子聚合物的基本单位,以可水解的2,4-戊二醇二丙烯酸盐(PODOA)为交联剂,合成高分子聚合物。用DNA凝胶迟滞实验验证聚合物与DNA的亲和力,以绿色荧光蛋白基因和萤光素酶检测其基因转染效率,用聚合物凝胶电泳实验鉴定其降解性,以MTT法检测其细胞毒性。结果:聚合物具有高的DNA结合亲和力、高基因转染效率,基因转染后的萤光素酶活性高达3×109RLU/mg,其基因转染效率相当于甚至优于目前市售的转染试剂,而细胞毒性明显低于其他试剂。该聚合物在中性环境下可降解,而在酸性条件下非常稳定。结论:合成的聚合物具有高转染效率和低细胞毒性,可能在转染和基因治疗研究中起重要作用。

Objective： To synthesize a new cationic polymer with high transfection efficiency and low cytotoxicity. Methods： Branched polyethyleneimine（PEI） PEI 600 was cross-linked by hydrolysisable 2,4-pentanediol diacrylate（2,4-PDODA） to synthesize high molecular weight polymers. The DNA binding affinity of synthesized polymers was determinated by DNA gel retardation assay, the gene transfection efficiency of polymers was evaluated in human embryo kidney HEK 293 cells by using green fluorescent protein and luciferase gene as reporter gene. The degradability and cytotoxicity of the polymer was analysized by agrose electrophoresis detection and M33＇ assay respectively. Results： The synthesized polymer showed high DNA binding affinity and high transfection efficiency. The luciferase activity of transfected 293 cell mediated by polymer was 3×10^9 RLU/mg, and showed similar or higher transfection efficiency as compare to commercial available transfection reagents. The polymer also showed lowest cytotoxicity. The polymer was very stable in acidic condition and highly degradable in neuture condition. Conclusion： It suggested that the synthesized polymer showed high transfection efficiency and low cytotoxicity. It may play important role in gene transfection and gene therapy study in the near future.