Novel bioreducible poly(amido amine)s for highly efficient gene delivery
Novel bioreducible poly(amido amine)s for highly efficient gene delivery
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DOI：
10.1021/bc060200l
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发表时间：
2007-01-01
影响因子：
4.7
通讯作者：
Engbersen, Johan F. J.
中科院分区：
文献类型：
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作者：
Lin, Chao;Zhong, Zhiyuan;Engbersen, Johan F. J.
合成了一系列新型的生物可还原多硫键聚（酰胺胺）（SS-PAA），并评价了其作为非病毒基因载体的性能。这些线性SS-PAA可以很容易地通过迈克尔型聚合加成不同的伯胺到含二硫化物的胱胺双丙烯酰胺。SS-PAA聚合物在模拟生理条件的介质（pH 7.4，150 mM PBS，37 ℃）中相对稳定，但在2.5 mM DTT存在下快速降解，模拟细胞内还原环境（pH 7.4，[R-SH] = 5 mM，37 ℃）。聚合物有效地将DNA缩合成纳米级（< 200 nm）和带正电荷（>+20 mV）的聚合复合物，其在中性条件下稳定，但在还原环境中迅速不稳定，如通过动态光散射测量和琼脂糖凝胶测定所揭示的。此外，大多数聚（酰胺基胺）在pH 7.4-5.1的pH范围内具有甚至高于聚乙烯亚胺（pEI）的缓冲能力，这是一种可有利地有助于聚合复合物的内体逃逸的性质。研究的7种SS-PAA中的4种的聚合复合物能够在体外转染COS-7细胞，其转染效率显著高于分支pEI，是迄今报道的最有效的聚合基因载体之一。重要的是，同样在血清存在下，当孵育时间从1 h延长至4 h时，可以观察到高水平的基因表达。XTT分析表明，SS-PAA和它们的复合物在观察到最高转染活性的浓度下基本上不具有或仅具有非常低的细胞毒性。结果表明，生物可还原聚酰胺-胺具有优良的性能，可用于开发高效、无毒的高分子基因载体。
A series of novel bioreducible poly(amido amine)s containing multiple disulfide linkages (SS-PAAs) were synthesized and evaluated as nonviral gene vectors. These linear SS-PAAs could be easily obtained by Michael-type polyaddition of various primary amines to the disulfide-containing cystamine bisacrylamide. The SS-PAA polymers are relatively stable in medium mimicking physiological conditions (pH 7.4, 150 mM PBS, 37 degrees C), but are rapidly degraded in the presence of 2.5 mM DTT, mimicking the intracellular reductive environment (pH 7.4, [R-SH] = 5 mM, 37 degrees C). The polymers efficiently condense DNA into nanoscaled (< 200 nm) and positively charged (>+20 mV) polyplexes that are stable under neutral conditions but are rapidly destabilized in a reductive environment, as was revealed by both dynamic light scatting measurement and agarose gel assays. Moreover, most of the poly(amido amine)s possess buffer capacities in the pH range pH 7.4-5.1 that are even higher than polyethylenimine (pEI), a property that may favorably contribute to the endosomal escape of the polyplexes. Polyplexes of four of the seven SS-PAAs studied were able to transfect COS-7 cells in vitro with transfection efficiencies significantly higher than those of branched pEI, being one of the most effective polymeric gene carriers reported to date. Importantly, also in the presence of serum, a high level of gene expression could be observed when the incubation time was elongated from 1 h to 4 h. XTT assays showed that SS-PAAs and their polyplexes possess essentially no or only very low cytotoxicity at concentrations where the highest transfection activity is observed. The results indicate that bioreducible poly(amido amine)s have excellent properties for the development of highly potent and nontoxic polymeric gene carriers.