In the progress of designing a gene carrier system, what is urgently needed is a balance of excellent safety and satisfactory efficiency. Herein, a straightforward and versatile synthesis of a cationic guanidine-decorated dendronized pullulan (OGG3P) for efficient genetic photodynamic therapy was proposed. OGG3P was able to block the mobility of DNA from a weight ratio of 2. However, G3P lacking guanidine residues could not block DNA migration until at a weight ratio of 15, revealing guanidination could facilitate DNA condensation via specific guanidinium-phosphate interactions. A zeta potential plateau (∼+23 mV) of OGG3P complexes indicated the nonionic hydrophilic hydroxyl groups in pullulan might neutralize the excessive detrimental cationic charges. There was no obvious cytotoxicity and hemolysis, but also enhancement of transfection efficiency with regard to OGG3P in comparison with that of native G3P in Hela and HEK293T cells. More importantly, we found that the uptake efficiency in Hela cells between OGG3P and G3P complexes was not markedly different. However, guanidination caused changes in uptake pathway and led to macropinocytosis pathway, which may be a crucial reason for improved transfection efficiency. After introducing a therapeutic pKillerRed-mem plasmid, OGG3P complexes achieved significantly enhanced KillerRed protein expression and ROS production under irradiation. ROS-induced cancer cells proliferation suppression was also confirmed. This study highlights the guanidine-decorated dendronized pullulan could emerge as a reliable nonviral gene carrier to specifically deliver therapeutic genes.
在设计
基因载体系统的过程中,迫切需要兼顾出色的安全性和令人满意的效率。本文提出了一种用于高效
基因光动力疗法的阳离子
胍装饰树枝化拉鲁兰(OGG3P)的直接、多功能合成方法。然而,缺乏
胍残基的 G3P 在重量比为 15 时才能阻止 DNA 迁移,这表明
胍化可通过特定的
胍-
磷酸相互作用促进 DNA 凝聚。OGG3P 复合物的 zeta 电位高原(∼+23 mV)表明,拉普兰中的非离子亲
水羟基可以中和过多的有害阳离子电荷。与原生 G3P 相比,OGG3P 在 Hela 和 HEK293T 细胞中没有明显的细胞毒性和溶血现象,而且还提高了转染效率。更重要的是,我们发现 OGG3P 和 G3P 复合物在 Hela 细胞中的吸收效率没有明显差异。然而,
鸟苷酸化引起了摄取途径的改变,并导致了大吞噬途径,这可能是提高转染效率的关键原因。引入治疗性 pKillerRed-mem 质粒后,OGG3P 复合物在辐照条件下显著增强了 KillerRed 蛋白的表达和 ROS 的产生。ROS 诱导的癌细胞增殖抑制也得到了证实。这项研究表明,
胍基装饰的树枝化拉鲁兰可以作为一种可靠的非病毒
基因载体,特异性地传递治疗
基因。