共载阿霉素和anti-miR-21寡核苷酸的多功能磁-介孔二氧化硅纳米复合粒子在逆转肿瘤多药耐药方面的研究

The two main causes of chemotherapy failure are absence of tumor targeting and multidrug resistance. Recent studies show that anti-miR-21 oligonucleotide plays a crucial role in reverse tumor multidrug resistance by rapidly and specifically silencing the expression of multidrug-resistance gene. Moreover, Magnetic-mesoporous silica nanocarriers have the characteristics of high medicine carrying and tumor targeting. This project based on our own previous study in successfully synthesis of the novel Fe3O4-SiO2 magnetic-mesoporous Janus particles, and we try to prepare a novel assembly system （Fe3O4-MSN/Dox-G2/anti-miR-21） with co-delivery of the classic cytotoxic drug doxorubicin (Dox) and anti-miR-21 oligonucleotide by magnetic-mesoporous Janus particles. The optimal parameters for loading and releasing drug were explored. In vivo MCF-7/Dox xenograft model was used to detect the effect of the novel assembly system on specific recognition, reversing MDR and inhibiting tumor growth. In vitro, fluorescence imaging was performed to visualize the released Dox and anti-miR-21 to investigate the mechanisms of endocytosis, release and response on in the novel assembly system in MCF-7 human breast cancer cell. Multidrug resistance relative proteins, such as Pgp、Bcl-2 and PDCD4 protein expression were determined to elucidate the molecular mechanisms of the novel assembly system on reversing multidrug resistance. The project will introduce a new method for clinical practice to decrease the adverse effect of chemotherapeutic drugs and reverse multidrug resistance.

肿瘤化疗药物缺乏靶向性和多药耐药是化疗失败的主要原因。基于anti-miR-21寡聚核苷酸快速、特异性沉默多药耐药相关基因，磁-介孔二氧化硅纳米载体肿瘤靶向性强、载药量高的特点，本项目在前期工作基础上，利用Janus型磁-介孔二氧化硅纳米载体共载化药阿霉素(Dox)和anti-miR-21，制备出集磁靶向、pH响应性和抗多药耐药为一体的多功能组装体（Fe3O4-MSN/Dox-G2/anti-miR-21），并研究其最佳载药和释药参数；整体水平探讨新组装体对肿瘤组织特异性识别、逆转肿瘤多药耐药及治疗作用；细胞水平通过荧光共定位揭示新组装体的细胞内吞、释放和响应机制；分子水平检测Pgp、Bcl-2、PDCD4等耐药基因蛋白表达，阐明组装体逆转多药耐药分子机制。实现化疗药物靶向运输至癌细胞、可控释放的同时，抑制肿瘤多药耐药性，进而提高化疗药物疗效，降低毒副作用，为临床肿瘤综合治疗提供全新方法。

肿瘤化疗药物缺乏靶向性和多药耐药是化疗失败的主要原因。基于anti-miR-21寡聚核苷酸快速、特异性沉默多药耐药相关基因，磁-介孔二氧化硅纳米载体肿瘤靶向性强、载药量高的特点，本项目利用Janus型磁-介孔二氧化硅纳米载体共载化药阿霉素(Dox)和anti-miR-21，制备出集磁靶向、pH响应性和抗多药耐药为一体的多功能组装体（Fe3O4-MSN/Dox /anti-miR-21），并研究其最佳载药和释药参数；细胞水平通过荧光共定位揭示新组装体的细胞内吞、释放和响应机制；整体水平探讨新组装体对肿瘤组织特异性识别、逆转肿瘤多药耐药及治疗作用；分子水平检测Pgp、Bcl-2、PDCD4等耐药基因蛋白表达，阐明组装体逆转多药耐药分子机制。本项目的结果表明通过优化反应条件我们制备出粒径合适、形貌均一的Janus型磁性介孔二氧化硅纳米粒子（M-MSNs），担载化疗药物DOX后的Janus型M-MSNs-DOX具备了外加磁场介导的靶向作用，证实Janus型M-MSNs-DOX可在体内外实现选择性肝癌治疗的效果，并具备了较好生物安全性。另外还证实外加磁场可增强Janus型M-MSNs-DOX的肝癌细胞内吞作用和在肿瘤部位的富集，增强了化疗药物的靶向性和抗耐药性。此项目证实Janus型M-MSNs-DOX作为多功能的纳米粒子有望实现化疗药物靶向运输至癌细胞、可控释放的同时，抑制肿瘤多药耐药性，进而提高化疗药物疗效，降低毒副作用，为临床肿瘤综合治疗提供全新方法。