Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan 430072, PR China.
Int J Pharm. 2012 Nov 15;438(1-2):191-201. doi: 10.1016/j.ijpharm.2012.08.039. Epub 2012 Aug 28.
To evaluate the effect of different peptides as well as their introduction methods on target gene transfer of gene vectors based on disulfide-containing polyethyleneimine (SS-PEI), a series of peptides including N(3)-GRGDSF, GRGDSF, and EEEEEEEEGRGDSF (E(8)GRGDSF) were prepared. N(3)-GRGDSF was conjugated to SS-PEI by click chemistry and SS-PEI-GRGDSF was obtained. GRGDSF was non-covalently introduced into SS-PEI/DNA mainly through hydrogen bonding to obtain SS-PEI/DNA/GRGDSF complexes, whereas E(8)GRGDSF was further non-covalently introduced to SS-PEI/DNA through electrostatic force to obtain SS-PEI/DNA/E(8)GRGDSF complexes. Transfection efficiency of all complexes with peptides was lower than that of SS-PEI/DNA in COS-7 cells due to the fact that nonspecific endocytosis was prohibited after peptide introduction. Whereas in HeLa cells, transfection activity of SS-PEI-GRGDSF/DNA and SS-PEI/DNA/E(8)GRGDSF at certain w/w ratios was higher than that of SS-PEI/DNA. But the transfection efficiency of SS-PEI/DNA/E(8)GRGDSF at peptide/DNA w/w ratios higher than 30 dropped due to targeted binding interactions between surplus E(8)GRGDSF and the integrins in HeLa cells, which would prohibit specific endocytosis of E(8)GRGDSF in complexes. Transfection activity of SS-PEI/DNA/GRGDSF was lower than or comparable to that of SS-PEI/DNA because of loose complexes constructed by hydrogen bonding between GRGDSF and SS-PEI/DNA.
为了评估不同肽及其引入方法对基于含二硫键的聚乙烯亚胺（SS-PEI）的基因载体的靶基因转染的影响，合成了一系列肽，包括 N(3)-GRGDSF、GRGDSF 和 EEEEEEEEGRGDSF（E(8)GRGDSF）。通过点击化学将 N(3)-GRGDSF 偶联到 SS-PEI 上，得到 SS-PEI-GRGDSF。GRGDSF 主要通过氢键非共价引入 SS-PEI/DNA 中，以获得 SS-PEI/DNA/GRGDSF 复合物，而 E(8)GRGDSF 通过静电力进一步非共价引入 SS-PEI/DNA 中，以获得 SS-PEI/DNA/E(8)GRGDSF 复合物。由于肽引入后禁止非特异性内吞作用，所有含肽复合物在 COS-7 细胞中的转染效率均低于 SS-PEI/DNA。然而，在 HeLa 细胞中，在一定 w/w 比下，SS-PEI-GRGDSF/DNA 和 SS-PEI/DNA/E(8)GRGDSF 的转染活性高于 SS-PEI/DNA。但是，由于多余的 E(8)GRGDSF 与 HeLa 细胞中的整合素之间的靶向结合相互作用，SS-PEI/DNA/E(8)GRGDSF 在肽/DNA w/w 比高于 30 时的转染效率下降，这会抑制 E(8)GRGDSF 在复合物中的特异性内吞作用。由于 GRGDSF 和 SS-PEI/DNA 之间通过氢键构建的复合物较松散，因此 SS-PEI/DNA/GRGDSF 的转染活性低于或可与 SS-PEI/DNA 相媲美。
