Key Laboratory of Green Chemistry and Technology (Ministry of Education), College of Chemistry, Sichuan University, Chengdu 610064, China.
Molecules. 2020 Feb 21;25(4):975. doi: 10.3390/molecules25040975.
The construction of efficient and low toxic non-viral gene delivery vectors is of great significance for gene therapy. Herein, two novel polycations were constructed via Michael addition from low molecular weight polyethylenimine (PEI) 600 Da and amino acid-containing linkages. Lysine and histidine were introduced for the purpose of improved DNA binding and pH buffering capacity, respectively. The ester bonds afforded the polymer biodegradability, which was confirmed by the gel permeation chromatography (GPC) measurement. The polymers could well condense DNA into nanoparticles and protect DNA from degradation by nuclease. Compared with PEI 25 kDa, these polymers showed higher transfection efficiency, lower toxicity, and better serum tolerance. Study of this mechanism revealed that the polyplexes enter the cells mainly through caveolae-mediated endocytosis pathway; this, together with their biodegradability, facilitates the internalization of polyplexes and the release of DNA. The results reveal that the amino acid-linked low molecular weight PEI polymers could serve as promising candidates for non-viral gene delivery.
高效低毒非病毒基因传递载体的构建对于基因治疗具有重要意义。在此，通过迈克尔加成反应，从低分子量聚乙烯亚胺（PEI）600 Da 和含氨基酸的连接物构建了两种新型聚阳离子。赖氨酸和组氨酸的引入分别提高了 DNA 结合能力和 pH 缓冲能力。酯键赋予聚合物可生物降解性，这通过凝胶渗透色谱（GPC）测量得到了证实。聚合物可以将 DNA 很好地凝聚成纳米颗粒，并保护 DNA 免受核酸酶的降解。与 25 kDa 的 PEI 相比，这些聚合物表现出更高的转染效率、更低的毒性和更好的血清耐受性。对这种机制的研究表明，聚合物纳米粒主要通过胞饮作用的小窝内吞途径进入细胞；这与它们的可生物降解性一起，促进了聚合物纳米粒的内化和 DNA 的释放。结果表明，氨基酸连接的低分子量 PEI 聚合物可用作非病毒基因传递的有前途的候选物。
