Wang Chang-Fang, Lin Yan-Xin, Jiang Tao, He Feng, Zhuo Ren-Xi
Key Laboratory of Biomedical Polymers of Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, China.
Biomaterials. 2009 Sep;30(27):4824-32. doi: 10.1016/j.biomaterials.2009.05.053. Epub 2009 Jun 17.
Polycations as one of non-viral vectors have gained increasing attentions. In this paper, polyethylenimine(PEI)-grafted polycarbonates (PMAC-g-PEIx) were synthesized as a kind of biodegradable polycations for gene delivery. Backbone polymer, poly(5-methyl-5-allyloxycarbonyl-trimethylene carbonate) (PMAC), was synthesized in bulk catalyzed by immobilized porcine pancreas lipase (IPPL). Then, PMAC-O, the allyl epoxidation product of PMAC, was further modified by PEIx with low molecular weight (x = 423, 800 and 1800). The MWs of PMAC-g-PEIx, measured by GPC-MALLS, were 81,900, 179,900 and 200,600 g/mol with polydispersities of 1.2, 1.4 and 1.7, respectively. PMAC-g-PEIx could form positively charged nano-sized particles (30-90 nm) with pDNA, and all the three PAMC-g-PEIx/DNA polyplexes had similar buffer capabilities. In vitro experiments demonstrated that the PAMC-g-PEIx showed much low cytotoxicity and enhanced transfection efficiency could be found in comparison with PEI25K in 293T cells. Furthermore, pre-incubation of PMAC-g-PEI1800 showed a weakening binding capacity with DNA. The biodegradability of PMAC-g-PEIx can facilitate the efficient release of pDNA from polyplexes and reduce cell cytotoxicity. These results suggested that PMAC-g-PEIx would be a promising non-viral biodegradable vector for gene delivery system.
聚阳离子作为非病毒载体之一已受到越来越多的关注。在本文中，合成了聚乙烯亚胺（PEI）接枝的聚碳酸酯（PMAC-g-PEIx）作为一种用于基因递送的可生物降解聚阳离子。主链聚合物聚（5-甲基-5-烯丙氧基羰基三亚甲基碳酸酯）（PMAC）通过固定化猪胰脂肪酶（IPPL）催化本体合成。然后，PMAC的烯丙基环氧化产物PMAC-O用低分子量的PEIx（x = 423、800和1800）进一步修饰。通过凝胶渗透色谱-多角度激光光散射（GPC-MALLS）测得的PMAC-g-PEIx的分子量分别为81,900、179,900和200,600 g/mol，多分散指数分别为1.2、1.4和1.7。PMAC-g-PEIx可与pDNA形成带正电的纳米级颗粒（30 - 90 nm），并且所有三种PAMC-g-PEIx/DNA复合物都具有相似的缓冲能力。体外实验表明，PAMC-g-PEIx表现出低得多的细胞毒性，并且与293T细胞中的PEI25K相比，转染效率有所提高。此外，PMAC-g-PEI1800的预孵育显示与DNA的结合能力减弱。PMAC-g-PEIx的生物可降解性可促进pDNA从复合物中的有效释放并降低细胞毒性。这些结果表明，PMAC-g-PEIx将是一种用于基因递送系统的有前途的非病毒可生物降解载体。
