荧光-磁双模态纳米载体装载Survivin siRNA 对胶质瘤干细胞增殖的影响及作用机制研究

The inhibition proliferation of targeted glioma stem cells (GSCs) is of great significance for the improvement of glioma treatment. Magnetic nanoparticles (MNPs) assisted siRNA delivery provides a promising technology for targeted inhibition of the proliferation of glioma stem cells (GSCs), and thus becomes an intensive focus for gene targeted therapy in glioma treatment, but its mechanism of regulating GSCs propagation remains unclear. On the basis of our previous related studies, in the present study, the heparin is used to couple with MNPs, and then the nanoparticles could be labeled by fluorescent dye interacted with the PEI amino residual, and epidermal growth factor (EGF) is then used to externally modify fluorescent-magnetic nanoparticles to synthesize the EGF modified fluorescent- magnetic bimodal nanocarriers. Combined with RNAi technology, the functionalized fluorescent-magnetic bimodal nanoparticles are used as the tumor cell targeted delivery carriers, after coupled with the tumorigenic gene Survivin siRNA to transport into GSCs. The transport of Survivin siRNA system, as well as the effects on proliferation of GSCs could be real-time monitored by magnetic resonance imaging (MRI) and near-infrared fluorescence imaging (NIRF), and the mechanism of underlying this nanoparticle delivered Survivin siRNA system to suppress tumor propagation could also be further explored with cytological and molecular methods. Therefore, the purpose of the present research is attempted to establish an efficiently and actively fluorescent magnetic dual-mode nanocarriers coupled with targeted siRNA system for glioma tumor therapy, and provides a theoretical basis for targeted therapy of glioma, and meanwhile offers valualbe cues to targeted therapy of other malignant tumors as well.

靶向抑制胶质瘤干细胞（GSCs）增殖对改善胶质瘤治疗效果具有十分重要的意义。以磁性纳米颗粒为载体的siRNA输送体系为靶向抑制GSCs增殖研究提供了一种颇具前景的技术，也是胶质瘤基因靶向治疗研究热点，但有关该体系调控GSCs增殖的影响和作用机制并不清楚。在前期工作基础上，本研究利用肝素偶联磁纳米颗粒，经荧光标记和表皮生长因子（EGF）功能化修饰，构建EGF主动靶向荧光-磁双模态纳米载体，结合RNAi技术，靶向输送Survivin siRNA至GSCs，利用磁共振成像和近红外荧光成像实时监测siRNA系统靶向输送过程，探索特异性抑制GSCs内源性凋亡抑制基因Survivin表达对其增殖的影响及作用机制。本研究通过构建以荧光-磁双模态纳米颗粒为载体的靶向GSCs输送siRNA体系并深入分析其作用机制，对进一步开展GSCs靶向治疗和研究具有重要的理论价值，为其它肿瘤的靶向治疗提供重要的理论参考。

胶质瘤干细胞（GSCs）被广泛认为是胶质瘤形成的“种子”细胞，在胶质瘤的发生、发展及复发过程中起到关键作用。本项目旨在构建具有GSCs靶向功能的siRNA及抗肿瘤药物输送纳米体系，探索特异性抑制GSCs内源凋亡抑制基因Survivin表达对其增殖的影响及作用机制。主要成果包括：（1）利用层层修饰的方法制备了具有良好靶向性、特异性及稳定性的表皮生长因子（EGF）功能化荧光-磁双模态纳米载体（eFMNs），且能够安全、高效地靶向输送Survivin siRNA及抗肿瘤药物（DOX）至GSCs，建立一种siRNA及抗肿瘤药物同步输送的新体系；（2）明确了靶向输送的Survivin/DOX siRNA能够显著抑制胶质瘤干细胞的增殖能力，引起凋亡，且二者具有协同增效的作用，并深入分析了其作用机制。本研究共发表高水平SCI研究论文5篇，申报发明专利2项，超额完成了预期目标。