Lu Bo, Sun Yun-Xia, Li Yun-Qiu, Zhang Xian-Zheng, Zhuo Ren-Xi
Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan, P. R. China.
Mol Biosyst. 2009 Jun;5(6):629-37. doi: 10.1039/b822505b. Epub 2009 Apr 17.
Low transfection efficiency and inactivation by serum are the major drawbacks for cationic polymers when used as non-viral gene vectors. Here, a series of N-succinyl-chitosan-graft-polyethylenimine (NSC-g-PEI) copolymers with different compositions were synthesized through grafting low molecular weight PEI (800 Da) to N-succinyl-chitosan. An agarose gel electrophoresis assay showed NSC-g-PEIs had good binding capability with DNA and the particle size of the NSC-g-PEI-DNA complexes was between 150 to 300 nm as determined by a Zeta sizer. In vitro transfection of NSC-g-PEI-DNA complexes for 293T, HeLa and CHO cells was investigated. It was found that the transfection efficiency of NSC-g-PEI-DNA complexes was higher than that of DNA combined PEI (25 kDa) and the transfection efficiency increased with the increasing GD of PEI. More importantly, the NSC-g-PEI-DNA complexes were stable and the transfection efficiency was not affected obviously in the presence of serum with different concentrations. In addition, NSC-g-PEIs had a lower cytotoxicity than PEI (25 kDa) and the toxicity increased with increasing GD of PEI. The NSC-g-PEI copolymers will have a good potential as efficient non-viral gene vectors in the presence of serum.
当用作非病毒基因载体时，阳离子聚合物的主要缺点是转染效率低和会被血清灭活。在此，通过将低分子量聚乙烯亚胺（800 Da）接枝到N-琥珀酰壳聚糖上，合成了一系列具有不同组成的N-琥珀酰壳聚糖-接枝-聚乙烯亚胺（NSC-g-PEI）共聚物。琼脂糖凝胶电泳分析表明，NSC-g-PEI与DNA具有良好的结合能力，通过Zeta粒度分析仪测定，NSC-g-PEI-DNA复合物的粒径在150至300 nm之间。研究了NSC-g-PEI-DNA复合物对293T、HeLa和CHO细胞的体外转染。发现NSC-g-PEI-DNA复合物的转染效率高于DNA与聚乙烯亚胺（25 kDa）结合的转染效率，且转染效率随聚乙烯亚胺接枝度（GD）的增加而提高。更重要的是，NSC-g-PEI-DNA复合物稳定，在不同浓度血清存在下，转染效率没有明显受到影响。此外，NSC-g-PEI的细胞毒性低于聚乙烯亚胺（25 kDa），且毒性随聚乙烯亚胺接枝度的增加而增加。在血清存在的情况下，NSC-g-PEI共聚物作为高效非病毒基因载体具有良好的潜力。
