Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
J Biomater Appl. 2013 Jul;28(1):112-24. doi: 10.1177/0885328212440344. Epub 2012 Aug 16.
One strategy for improving gene vector properties of polyethylenimine is to facilitate individual transfection mechanism steps. This study investigates (i) improving transfection efficiency by attaching peptide nuclear localization signals (nuclear localization signals: SV40 large T antigen nuclear localization signal or C-terminus of histone H1) to polyethylenimine (10 kDa) and (ii) using disulfide linkages, which are expected to be stable during polyplex formation, but cleaved inside cells giving improved gene release. Nuclear localization signal-containing polyplexes exhibited low cytotoxicity, whereas transfection efficiency with high molecular weight plasmid DNA increased up to 3.6 times that of underivatized polyethylenimine in Neuro2A cells at higher molar ratio of polyethylenimine-nitrogen to DNA-phosphate (N/P) ratios. However, with luciferase-specific low molecular weight small interfering RNA in Neuro2A/EGFPLuc cells, nuclear localization signal-containing polyplexes with disulfide linkages caused substantial cytotoxicity at N/P ratios >15 and no consistent significant reduction in luciferase expression. Possible explanations for molecular weight-dependent differences in genetic information transfer by polyplexes containing disulfide-linked nuclear localization signals are discussed.
提高聚乙烯亚胺基因载体性质的一种策略是促进个体转染机制步骤。本研究调查了（i）通过将肽核定位信号（核定位信号：SV40 大 T 抗原核定位信号或组蛋白 H1 的 C 末端）连接到聚乙烯亚胺（10 kDa）来提高转染效率，以及（ii）使用二硫键，预计在形成多聚物时稳定，但在细胞内裂解以提高基因释放。含有核定位信号的多聚物表现出低细胞毒性，而在用更高的聚乙烯亚胺-氮与 DNA-磷（N/P）比值的摩尔比处理时，高分子量质粒 DNA 的转染效率高达未经修饰的聚乙烯亚胺的 3.6 倍。然而，在 Neuro2A/EGFPLuc 细胞中用针对荧光素酶的特异性小分子干扰 RNA 处理时，含有二硫键的核定位信号的多聚物在 N/P 比>15 时会引起明显的细胞毒性，并且对荧光素酶表达没有一致的显著降低。讨论了含有二硫键连接的核定位信号的多聚物在遗传信息传递方面因分子量而异的可能解释。
