刺激响应性非病毒转基因载体

常见的阳离子聚合物能够通过静电作用有效缩合DNA,形成聚电解质复合物（PECs）。这些复合物易于细胞内在化,从内涵体中逃逸,并能保护DNA免受DNA酶的降解。但是,强烈的静电作用也限制了基因进入细胞核之后从复合物中的释放,限制了基因的表达。鉴于此,科学家们设计了一类“智能”高分子载体,这些智能高分子载体能够响应外界微环境温度、pH值和氧化还原环境变化的刺激,其自身大分子构象发生改变,进而促进DNA从复合物中逃逸,提高了转染率。本文介绍了近年来有关聚异丙基丙烯酰胺基温度响应性载体以及光、pH和响应胞内谷胱甘肽（GSH）等氧化还原反应的非病毒转基因载体的研究进展。

Stimuli-responsive Non-viral Gene Delivery Vectors

Polycations are able to form stable polyelectroylte complexes (PECs) with DNA via strong electrostatic interaction. The PECs are favorable for an efficient DNA condensation to facilitate cell internalization, endolysosomal escape and protect DNA from DNase attacking. However, tight compaction of DNA in complexes tends to prevent its release from its carrier, deteriorating the ultimate gene expression. In light of this demerit inherent to PECs, a new type of smart or intelligent polymer vectors have been designed. These smart polymers are capable of responding to microenviromental changes, such as temperature, pH and the redox by varying macromolecular conformation, which aids in unpacking DNA from complex, consequently increasing transfection efficiency. This article presents the recent progress in poly(N-isopropylacrylamide)-based temperature, light, intracellular pH and glutathione responsive non-viral vectors.