A releasable disulfide carbonate linker for polyethyleneimine (PEI)-based gene vectors
作者:Liandong Feng、Aming Xie、Xinyu Hu、Yangyang Liu、Jianfa Zhang、Shufeng Li、Wei Dong
DOI:10.1039/c4nj00699b
日期:——
In this study, a releasable disulfide carbonate linker is used to prepare disulfide-containing crosslinked polyethyleneimines (PEI-SS-CLs) for gene delivery. ESI-MS analysis shows that after being incubated with 1,4-dithio-DL-threitol (DTT), the degradable linkages in the polyethyleneimine (PEI) derivatives undergo disulfide bond cleavage followed by intramolecular cyclization and cleavage of the neighboring carbamate bond. Moreover, it is observed that thiol/polyanions trigger the release of DNA from polyplexes via the reductive degradability of PEI-SS-CLs and ion-exchange. In vitro transfection results indicate that PEI-SS-CL-1.5 (at a crosslinker/PEI feed molar ratio of 1.5) exhibits higher transfection efficacy than the commercially available reagents such as the high molecular weight PEI with a molecular weight of 25 kDa (PEI 25k) and the versatile liposomes Lipofectamine 2000. PEI-SS-CL-1.5 also demonstrates significantly lower cytotoxicity, compared with PEI 25k and Lipofectamine 2000. Our study indicates that incorporating the thiol-specific cleavable disulfide bond into crosslinked PEIs and implementing regulated release of DNA are effective strategies for designing safe and effective gene vectors.
在本研究中,使用可释放的二硫代碳酸盐连接子制备了含有二硫键的交联聚乙烯亚胺(PEI-SS-CLs)用于基因传递。ESI-MS分析显示,在与1,4-二硫代-DL-苏糖醇(DTT)孵育后,聚乙烯亚胺(PEI)衍生物中的可降解连接子经历了二硫键断裂,随后发生分子内环化及邻近的氨基甲酸酯键断裂。此外,观察到硫醇/多阴离子通过PEI-SS-CLs的还原降解性和离子交换触发多聚复合物中DNA的释放。体外转染结果表明,PEI-SS-CL-1.5(交联剂/PEI投料摩尔比为1.5)的转染效率高于商业上可用的高分子量PEI(分子量为25 kDa,PEI 25k)和多用途脂质体Lipofectamine 2000。与PEI 25k和Lipofectamine 2000相比,PEI-SS-CL-1.5还显示出显著更低的细胞毒性。我们的研究结果表明,将特定于硫醇的可裂解二硫键整合到交联PEI中并实现DNA的受调控释放,是设计安全有效基因载体的方法。