多模态层级靶向脑胶质瘤siRNA纳米影像载体系统可控制备与抑瘤活性研究

Glioma is one of major malignacy to give threat to human life and health, the rapid development of RNAi technology is expected to provide solutions for the treatment of glioma. siRNA administration to the brain tumors need to overcome the two basic difficulties for the blood-brain barrier and tissue/cell targeted delivey. Based on our previous results for successfully prepared magnetic nanocarrier for siRNA delivery, this project focuses on surface structure controllable preparation of water-soluble graphitic carbon shell magnetic nanomaterials,fuctionalized with blood-brain barrier penetrating peptide and cell-penetrating peptide fusion peptide, and glioma targeting vascular VEGF aptamers by host-guest chemistry, highly efficient load fluorescently labeled cell adhesion protein JAM2 siRNA mediated by pH sensitive proton-sponge polymer modificaton, innovativly build up brain glioma cascade-targeting siRNA delivery imaging carrier based on MRI , NIR, multi-modal fluorescent tracer. The study aims to explore the GMN-siRNA composite system structure-activity relationship by use of FLUC-mCherry glioma animal model; Investigate the effects of controlled intracelluar release of JAM2 siRNA on glioma cells proliferation, migration and angiogenesis, clarify its mechanism of action, so as to achieve the in vivo siRNA system delivery targeting glioma.

脑胶质瘤是威胁人类生命健康的重大恶性肿瘤之一,RNAi技术的快速发展有望为治疗脑胶质瘤提供解决方案。siRNA脑瘤给药需要克服血脑屏障和组织细胞内靶向传递两个基本困难。本课题拟在前期成功制备siRNA高效转染磁性纳米粒子研究基础之上，表面结构可控制备水溶性石墨碳壳磁性纳米材料GMN，主客体化学法自组装交联血脑屏障穿越肽与细胞穿膜肽融合多肽以及靶向胶质瘤血管VEGF aptamers等多功能分子配体，通过pH敏感质子海绵体聚合物修饰高效负载荧光标记的细胞黏附蛋白JAM2 siRNA，创新性构建层级靶向脑胶质瘤基于MRI、NIR、荧光成像的多模态siRNA纳米影像载体系统。以FLUC-mCherry脑瘤动物模型为研究对象，探讨GMN-siRNA复合体系构效关系；研究JAM2 siRNA细胞内控制释放对胶质瘤增殖、迁移及血管形成的影响，阐明其作用机制，从而实现体内siRNA靶向脑胶质瘤系统给药。

脑胶质瘤目前仍然是最难克服的肿瘤之一，siRNA药物是有效提高肿瘤杀伤效果的药物分子，siRNA靶向给药系统建立对于实现肿瘤靶向抑制作用具有重要意义。而诊疗一体化siRNA多模态纳米影像系统开发对于实现脑胶质瘤早期诊断与靶向治疗具有重要临床价值。本项目重点研究了siRNA靶向转染金磁性纳米影像载体系统合成条件，靶向转染JAM2 siRNA以及VEGF-Notch3chimera分子的转染效率，体内外抗肿瘤效果以及作用机制。本课题成功构建了多模态siRNA/chimera高效转染金磁性纳米粒子载体系统，对其理化性质进行了表征，探明了复合纳米粒子影像载体系统体内抗肿瘤活性及作用机制。如期完成了项目申请预期研究内容，取得了预期研究效果。结果表明，Au-Fe3O4-chimera复合药物体系能够特异性杀伤顺铂耐药性肿瘤细胞株SKOV3细胞，表明通过纳米载体高效转染VEGF-Notch3 chimera进入肿瘤细胞后，能够通过特异性抑制Notch3基因表达实现提高耐药性肿瘤细胞对顺铂药物敏感性。本课题开创性构建了非对称结构金磁性纳米粒子基因/化疗药物双载体系统，实现了对siRNA, chimera分子以及化疗药物顺铂的联合靶向给药。提高了对顺铂耐药性细胞的靶向杀灭效果，揭示了卵巢癌耐药性作用机制，为开发新型抗肿瘤靶向药物系统奠定了基础。