PEG-detachable polyplex micelles based on disulfide-linked block catiomers as bioresponsive nonviral gene vectors
PEG-detachable polyplex micelles based on disulfide-linked block catiomers as bioresponsive nonviral gene vectors
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DOI：
10.1021/ja800336v
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发表时间：
2008-05-07
影响因子：
15
通讯作者：
Kataoka, Kazunori
中科院分区：
文献类型：
--
作者：
Takae, Seiji;Miyata, Kanjiro;Kataoka, Kazunori
基于聚乙二醇（PEG）的多聚复合物胶束被开发为非病毒基因载体，它能够响应细胞内的还原环境而使周围的PEG链脱离。一种新型的嵌段阳离子聚合物PEG - SS - P[Asp(DET)]是这样设计的：（i）在PEG和聚阳离子链段之间插入可生物裂解的二硫键以触发PEG脱离；（ii）基于聚天冬酰胺的阳离子链段带有侧翼的N -（2 - 氨乙基）- 2 - 氨乙基，即P[Asp(DET)]，其中Asp(DET)单元作为缓冲部分，以最小的细胞毒性诱导内涵体逃逸。由PEG - SS - P[Asp(DET)]和质粒DNA（pDNA）形成的多聚复合物胶束由于亲水性PEG栅栏的形成而稳定地分散在水介质中，尺寸分布范围较窄，约为80nm，而在化学计量电荷比下加入10mM二硫苏糖醇（DTT）时会发生聚集，这表明PEG通过二硫键的裂解从胶束上脱离。与不含二硫键的PEG - P[Asp(DET)]胶束相比，PEG - SS - P[Asp(DET)]胶束的基因转染效率高1 - 3个数量级，且基因表达起始更快，这是因为基于内涵体中PEG的脱离，其内涵体逃逸更为有效。这些发现表明，PEG - SS - P[Asp(DET)]胶束作为一种非病毒基因载体具有良好的潜力，能够在可调控的时间内实现高效转染且细胞毒性最小。
PEG-based polyplex micelles, which can detach the surrounding PEG chains responsive to the intracellular reducing environment, were developed as nonviral gene vectors. A novel block catiomer, PEG-SS-P[Asp(DET)], was designed as follows: (i) insertion of biocleavable disulfide linkage between PEG and polycation segment to trigger PEG detachment and (ii) a cationic segment based on poly(aspartamide) with a flanking N-(2-aminoethyl)-2-aminoethyl group, P[Asp(DET)], in which the Asp(DET) unit acts as a buffering moiety inducing endosomal escape with minimal cytotoxicity. The polyplex micelles from PEG-SS-P[Asp(DET)] and plasmid DNA (pDNA) stably dispersed in an aqueous medium with a narrowly distributed size range of similar to 80 nm due to the formation of hydrophilic PEG palisades while undergoing aggregation by the addition of 10 mM dithiothreitol (DTT) at the stoichiometric charge ratio, indicating the PEG detachment from the micelles through the disulfide cleavage. The PEG-SS-P[Asp(DET)l micelles showed both a 1-3 orders of magnitude higher gene transfection efficiency and a more rapid onset of gene expression than PEG-P[Asp(DET)] micelles without disulfide linkages, due to much more effective enclosomal escape based on the PEG detachment in endosome. These findings suggest that the PEG-SS-P[Asp(DET)] micelle may have promising potential as a nonviral gene vector exerting high transfection with regulated timing and minimal cytotoxicity.