Polyphosphoramidate gene carriers: effect of charge group on gene transfer efficiency
Polyphosphoramidate gene carriers: effect of charge group on gene transfer efficiency
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DOI：
10.1038/sj.gt.3302248
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发表时间：
2004-06-01
期刊：
影响因子：
5.1
通讯作者：
Leong, KW
中科院分区：
文献类型：
--
作者：
Wang, J;Gao, SJ;Leong, KW
阳离子聚合物载体已广泛用于基因递送。然而，结构与功能的关系，特别是阳离子聚合物载体的电荷基团对转染活性的影响，知之甚少。为了检查这一重要参数，合成了一系列阳离子聚合物，即具有相同主链、相同侧链间隔基、相似分子量但含有伯氨基至季氨基的不同电荷基团的聚氨基磷酸酯（PPA）（PPA-EA、PPA-MEA、PPA-DMA和PPA-TMA，图1）。4种PPA与DNA的结合力依次为PPA-EA < PPA-MEA < PPA-DMA similar to PPA-TMA. The cytotoxicity decreased in the order of PPA-EA >PPA-MEA > PPA-DMA > PPA-TMA。四种不同类型的PPA/DNA纳米颗粒的粒径和zeta电位与PPA结构没有显着的相关性。这些PPA在pH 5-7内没有显示出显著的缓冲能力，即使由PPA-EA介导的转染似乎是唯一受内溶体逃逸限制的转染。对于所有四种PPA，PPA介导的DNA内吞作用也相似（17-22%）。然而，这些PPA的转染效率差异显着。PPAs体外转染效率的顺序为PPA-EA > PPA-MEA > PPA-DMA，与PPA-TMA相似。具有含伯氨基的PPA-EA的纳米颗粒在611至20/1（+ /-）的电荷比下在细胞系中产生最高的转染效率。与体外观察到的转染效率的趋势相匹配，PPA-EA在鞘内注射纳米颗粒后在脊髓中介导了与聚乙烯亚胺相当的最高转基因表达。这些结果表明，在体外和鞘内基因递送模型中，具有伯氨基侧链的PPA基因载体比具有仲、叔或季氨基的PPA基因载体更有效。
Cationic polymeric carriers have been widely used for gene delivery. However, the structure-function relationship, especially the effect of charge groups of cationic polymeric carriers on the transfection activity, is poorly understood. To examine this important parameter, a series of cationic polymers, polyphosphoramidates (PPAs) with an identical backbone, same side chain spacer, similar molecular weights but different charge groups containing primary to quaternary amino groups (PPA-EA, PPA-MEA, PPA-DMA and PPA-TMA, Figure 1) were synthesized. The DNA-binding affinity of these four PPAs increased in the order of PPA-EA < PPA-MEA < PPA-DMA similar to PPA-TMA. The cytotoxicity decreased in the order of PPA-EA > PPA-MEA > PPA-DMA > PPA-TMA. Particle size and zeta potential of four different types of PPA/DNA nanoparticles did not show significant correlation with PPA structure. These PPAs did not show significant buffering capacity within pH 5-7, even though transfection mediated by PPA-EA was the only one that seemed to be limited by endolysomal escape. Endocytosis of DNA mediated by PPAs was also similar (17-22%) for all four PPAs. However, the transfection efficiency of these PPAs varied significantly. In vitro transfection efficiency of PPAs decreased in the order of PPA-EA > PPA-MEA > PPA-DMA similar to PPA-TMA. Nanoparticles with PPA-EA containing primary amino groups gave the highest transfection efficiency in cell lines at the charge ratios from 611 to 20/1 (+ /-). Matching the trend of transfection efficiency observed in vitro, PPA-EA mediated the highest transgene expression, comparable to that of polyethylenimine, in the spinal cord following intrathecal injection of the nanoparticles. These results establish that PPA gene carriers with primary amino group side chains are more potent than those with secondary, tertiary or quaternary amino groups in vitro and in the intrathecal gene delivery model.