Abstract

To achieve biocompatibility and high gene transfection efficiency, developing new cationic polymers with natural functional moieties has been regarded as a promising way. In this work, histidine was grafted on chitosan (CS) to produce CS derivatives (HGCS) for siRNA delivery and the HGCS/siRNA complexes were formed by the self-assembly method. The structures of histidine grafted CS polymers were characterized by FT-IR and XRD. The Acid-base titration assay was used to measure their proton buffering capacities and results indicated HGCS polymers have stronger buffering capacity than unmodified CS. The particle size, zeta potential and the stability of the polymer/siRNA complexes were measured by laser particle size analyzer and gel retardation assay. The cytotoxicity of polymers was determined by MTT assays in RSC96 cells. Moreover, cellular uptake investigation into polymer/siRNA complexes demonstrated that HGCS polymers have efficient siRNA transfection ability in B16F1 cells and HeLa cells. These data suggest HGCS polymers as a hopeful non-viral gene delivery vectors.

摘要

为了实现生物相容性和高基因转染效率，开发具有天然功能部分的新型阳离子聚合物被认为是一种很有前途的方法。在这项工作中，将组氨酸嫁接在壳聚糖（CS）上以产生用于siRNA递送的CS衍生物（HGCS），并通过自组装方法形成HGCS / siRNA复合物。通过FT-IR和XRD表征了组氨酸接枝CS聚合物的结构。酸碱滴定法用于测量它们的质子缓冲能力，结果表明 HGCS 聚合物比未改性的 CS 具有更强的缓冲能力。通过激光粒度分析仪和凝胶阻滞测定法测量聚合物/siRNA复合物的粒度、zeta电位和稳定性。聚合物的细胞毒性通过 MTT 测定在 RSC96 细胞中测定。而且，对聚合物/siRNA 复合物的细胞摄取研究表明，HGCS 聚合物在 B16F1 细胞和 HeLa 细胞中具有高效的 siRNA 转染能力。这些数据表明 HGCS 聚合物是一种有希望的非病毒基因递送载体。