载siRNA的壳聚糖外壳磷酸钙纳米粒治疗宫颈癌研究

摘要

本研究设计构建一种壳聚糖包被的磷酸钙纳米粒子(CS/CaP /siRNA)递送siRNA用于宫颈癌治疗.通过纳米沉淀法制备得到均一球形的CS/CaP/siRNA纳米粒,其粒径约为194 nm,ξ电位约为+27 mV.体外实验证明该纳米粒可以有效地递送siEGFR到Hela细胞中并显著下调EGFR表达水平,这可能与壳聚糖的细胞粘附性增强而延长了细胞摄取时间有关.此外,被摄取进入胞内的纳米粒表现出pH响应性纳米粒子膨胀最后解散导致siRNA释放从而促进siRNA从溶酶体快速地逃逸到胞浆内.此外,裸鼠异位接种宫颈癌瘤内注射疗效结果显示CS/CaP/siEGFR纳米粒具有高效的肿瘤生长抑制效应,且整个实验期间体重无明显变化.所有这些结果表明CS/CaP/siRNA纳米粒将有可能通过粘膜给药方式治疗宫颈癌.%In the present study,a chitosan-coated calcium phosphate nanoparticle (CS/CaP/siRNA NP) was developed to deliver siRNA for treatment of cervical cancer.The CS/CaP/siRNA NPs were prepared by the nano-precipitation method.The resulted NPs had a uniform spherical morphology with a size of～194 nm and a zeta potential of～+27 mV.In vitro experiments demonstrated that these NPs could efficiently deliver siEGFR into Hela cells and significantly down-regulate the EGFR expression level,which was probably associated with enhanced cell adhesion of chitosan,leading to extended residence time of cell internalization.Then the internalized CS/CaP/siRNA NPs exhibited pH-responsive disassembly of NPs,resulting in the enhanced release of siRNA and rapid lysosomal escape into cytoplasm.Moreover,in vivo anticancer results showed that the CS/CaP/siRNA NPs had significant inhibitory effects on tumor growth after intratumoral injection in Hela tumor xenografted nude mice,accompanying with no obvious changes of body weight during the whole experimental period.All these results indicated that the CS/CaP/siRNA NPs would have great potential to deliver siRNA for the treatment of cervical cancer via mucosal administration.