Liu Shuai, Zhou Dezhong, Yang Jixiang, Zhou Hao, Chen Jiatong, Guo Tianying
Key Laboratory of Functional Polymer Materials, Ministry of Education, Institute of Polymer Chemistry, College of Chemistry, Nankai University , Tianjin 300071, China.
Department of Biochemistry and Molecular Biology, College of Life Science, Nankai University , Tianjin 300071, China.
J Am Chem Soc. 2017 Apr 12;139(14):5102-5109. doi: 10.1021/jacs.6b13337. Epub 2017 Mar 30.
To transform common low-molecular-weight (LMW) cationic polymers, such as polyethylenimine (PEI), to highly efficient gene vectors would be of great significance but remains challenging. Because LMW cationic polymers perform far less efficiently than their high-molecular-weight counterparts, mainly due to weaker nucleic acid encapsulation, herein we report the design and synthesis of a dipicolylamine-based disulfide-containing zinc(II) coordinative module (Zn-DDAC), which is used to functionalize LMW PEI (M ≈ 1800 Da) to give a non-viral vector (Zn-PD) with high efficiency and safety in primary and stem cells. Given its high phosphate binding affinity, Zn-DDAC can significantly promote the DNA packaging functionality of PEI and improve the cellular uptake of formulated polyplexes, which is particularly critical for hard-to-transfect cell types. Furthermore, Zn-PD polymer can be cleaved by glutathione in cytoplasm to facilitate DNA release post internalization and diminish the cytotoxicity. Consequently, the optimal Zn-PD mediates 1-2 orders of magnitude higher gluciferase activity than commercial transfection reagents, Xfect and PEI, across diverse cell types, including primary and stem cells. Our findings provide a valuable insight into the exploitation of LMW cationic polymers for gene delivery and demonstrate great promise for the development of next-generation non-viral vectors for clinically viable gene therapy.
将常见的低分子量（LMW）阳离子聚合物，如聚乙烯亚胺（PEI），转化为高效基因载体具有重要意义，但仍具有挑战性。由于低分子量阳离子聚合物的效率远低于其高分子量对应物，主要原因是核酸包封能力较弱，在此我们报道了一种基于二吡啶甲胺的含二硫键锌（II）配位模块（Zn-DDAC）的设计与合成，该模块用于对低分子量PEI（M≈1800 Da）进行功能化，以得到在原代细胞和干细胞中具有高效性和安全性的非病毒载体（Zn-PD）。鉴于其对磷酸盐的高结合亲和力，Zn-DDAC可显著促进PEI的DNA包装功能，并改善所制备的多聚体的细胞摄取，这对于难以转染的细胞类型尤为关键。此外，Zn-PD聚合物可被细胞质中的谷胱甘肽裂解，以促进内化后DNA的释放并降低细胞毒性。因此，在包括原代细胞和干细胞在内的多种细胞类型中，最佳的Zn-PD介导的荧光素酶活性比市售转染试剂Xfect和PEI高1-2个数量级。我们的研究结果为开发用于基因递送的低分子量阳离子聚合物提供了有价值见解，并为开发用于临床可行基因治疗的下一代非病毒载体展示了巨大前景。
