School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Tianjin 300350, China.
J Mater Chem B. 2019 Mar 21;7(11):1906-1919. doi: 10.1039/c8tb03085e. Epub 2019 Feb 15.
Gene delivery systems with good biocompatibility and high transfection efficiency play a major role in the clinical application of gene therapy. It is of great interest to develop a functional anionic polymer to modify polycationic carriers for the purpose of improving their biocompatibility and gene delivery ability. Herein, we prepared three kinds of anionic polymers, i.e., cis-aconitic anhydride grafted poly(l-lysine) (PLCA), cis-aconitic anhydride and CAGW functional peptide grafted poly(l-lysine) (PLCA-CAGW), and succinic anhydride and CAGW peptide grafted poly(l-lysine) (PLSA-CAGW), and coated them onto binary gene complexes to obtain three ternary complexes, i.e., TCP-CA, TCP-CA-CAGW and TCP-SA-CAGW, respectively. These gene delivery systems were integrated with a specific functional peptide and smart polyplexes that enabled them to perform a desired function in response to pH changes in biological microenvironments. The results of the cell viability assay showed that the prepared anionic polymers could improve the biocompatibility of gene complexes. Gene expression at the mRNA and protein levels demonstrated that TCP-CA-CAGW enhanced the gene delivery efficiency, benefiting from the targeting CAGW peptide and charge reversal moiety (cis-aconitic amide), while TCP-SA-CAGW showed a relatively low transfection efficiency because of negatively charged PLSA-CAGW and its non-reversal function. The PLCA-CAGW shell in TCP-CA-CAGW possessed an aconitic acid group, EC targeting ligand and charge reversal cis-aconitic amide, which enabled the gene delivery systems to be neutral in blood circulation, but once in the acidic lysosomes, they became positively charged for improving lysosomal escape and nuclear localization. Importantly, the in vitro/vivo angiogenesis assay demonstrated that human umbilical vein endothelial cells transfected with TCP-CA-CAGW functionalized ternary complexes could obviously enhance vascularization. These multifunctional ternary complexes with functional smart anionic polymer shells possessed low cytotoxicity and high gene delivery efficiency, and this strategy may be a promising platform for cardiovascular gene therapy.
具有良好生物相容性和高转染效率的基因传递系统在基因治疗的临床应用中起着重要作用。开发一种功能性阴离子聚合物来修饰阳离子载体，以提高其生物相容性和基因传递能力，这是非常有趣的。本文制备了三种阴离子聚合物，即顺式乌头酸酐接枝聚（L-赖氨酸）（PLCA）、顺式乌头酸酐和 CAGW 功能肽接枝聚（L-赖氨酸）（PLCA-CAGW）和琥珀酸酐和 CAGW 肽接枝聚（L-赖氨酸）（PLSA-CAGW），并将它们涂覆到二元基因复合物上，分别得到三种三元复合物，即 TCP-CA、TCP-CA-CAGW 和 TCP-SA-CAGW。这些基因传递系统与特定功能肽集成在一起，智能的超分子聚合物能够使其在生物微环境的 pH 变化下发挥预期的功能。细胞活力测定结果表明，所制备的阴离子聚合物能够提高基因复合物的生物相容性。mRNA 和蛋白质水平的基因表达表明，TCP-CA-CAGW 增强了基因传递效率，这得益于靶向 CAGW 肽和电荷反转部分（顺式乌头酸酰胺），而 TCP-SA-CAGW 显示出相对较低的转染效率，这是由于带负电荷的 PLSA-CAGW 及其非反转功能。TCP-CA-CAGW 中的 PLCA-CAGW 壳具有顺式乌头酸基团、EC 靶向配体和电荷反转的顺式乌头酸酰胺，使基因传递系统在血液循环中呈中性，但一旦进入酸性溶酶体，它们就会带正电荷，以提高溶酶体逃逸和核定位。重要的是，体外/体内血管生成试验表明，转染 TCP-CA-CAGW 功能化三元复合物的人脐静脉内皮细胞明显增强了血管生成。这些具有功能性智能阴离子聚合物壳的多功能三元复合物具有低细胞毒性和高基因传递效率，这种策略可能是心血管基因治疗的有前途的平台。
