For efficient gene delivery, non-viral vectors should have high cellular uptake, excellent endosomal escape, and the ability to rapidly release the gene into the cytoplasm. Here, we developed a disulfide bond-conjugated bioreducible LMWSC-g-bPEI (LCP) composed of low molecular-weight water soluble chitosan (LMWSC), bPEI, and cystamine (Cys). The developed LCP had advantages such as low toxicity, great endosomal escape, and rapid release of pDNA into the cytoplasm. The polyplexes with LCP showed higher uptake into the nucleus and greater transfection efficiency than that without disulfide bond. Moreover, LCP polymer and polyplexes with LCP indicated lower cytotoxicity than bPEI 25 kDa. In addition, a gel retardation assay and particle size were analyzed to demonstrate the reduction-sensitive gene delivery system. Besides, intracellular uptake pathway of polyplexes was investigated by various endocytosis inhibitor and confirmed to internalization into cell via macropinocytosis. These results suggest that bioreducible LCP is a superb non-viral vector for efficient gene delivery.

中文翻译：

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评价二硫键结合的LMWSC- g -bPEI作为非病毒载体的低细胞毒性和高效基因传递

为了有效地传递基因，非病毒载体应具有较高的细胞摄取率，出色的内体逃逸性以及将基因快速释放到细胞质中的能力。在这里，我们开发了一种二硫键结合的生物可还原的LMWSC- g-bPEI（LCP）由低分子量水溶性壳聚糖（LMWSC），bPEI和胱胺（Cys）组成。所开发的LCP具有诸如低毒性，大量的内体逃逸以及将pDNA快速释放到细胞质中的优点。与没有二硫键的复合物相比，具有LCP的复合物显示出更高的摄入核和更高的转染效率。此外，LCP聚合物和具有LCP的多聚物显示出比bPEI 25 kDa更低的细胞毒性。另外，分析了凝胶阻滞测定法和粒径，以证明还原敏感性基因递送系统。此外，通过多种内吞抑制剂研究了多链体的细胞内摄取途径，并证实其可通过以下途径内化进入细胞巨胞饮作用。这些结果表明，可生物还原的LCP是高效基因传递的绝佳非病毒载体。