PPI-DNA复合物的制备和PPI载体的细胞毒性研究

Preparation of PPI-DNA complex and study of cytotoxicity of PPI vector

目的研究2.0代聚丙烯亚胺树状物(2.0G PPI)和单甲氧基聚乙二醇(mPEG)的修饰物(PPI-PEG)与DNA的复合物的制备和PPI的细胞毒性。方法用丁二酸酐和琥珀酰亚胺两步活化的mPEG耦联到PPI的氨基上,得到PPI-PEG,应用现代波谱等技术对中间体和最终产物进行表征。采用绿色荧光蛋白基因质粒pEGFP-N1为DNA模型,凝胶点用法研究了PPI和PPI-PEG与DNA的复合,并且采用MTT法测定它们的细胞毒性。结果凝胶电泳数据显示PPI阻滞了DNA在琼脂糖凝胶中电泳,MTT数据显示PPI对细胞具有一定毒性。结论PPI作为基因载体可以与DNA形成复合物,且PPI偶联上PEG后毒性降低。

Objective This paper studied the preparation of PPI/DNA complex and PPI-PEG/DNA complex, cytotoxicity of PPI as gene vector. Method PPI-PEG was prepared by mPEG （ methoxypolyethlene glycolyl） ） which was activated with succinimidyl succinate in two steps was grafted to the amino group of poly （propylene imine） （PPI） dendrimer in this paper. The structure of the mediate product and mPEG-PPI were confirmed with 1HNMR and Fourier transform infrared（FTIR） spectrum. Plasmid pEGFP - N1 was chosen as model DNA. Result The data of Agarose gel electrophoresis of pDNA-PPI complex shows PPI blocked DNA, the data of MTY demonstrates PPI has cytotoxicity. Conclusion The study of PPI/DNA complex and cytotoxicity of 2.0G PPI dendrimer demonstrates that 2.0G PPI dendrimer is capable of condensing DNA and the cytotoxicity is fairly high, while the modification with PEG of PPI can significantly suppress the cytotoxicity.