"三位一体"式逆转肿瘤MDR智能靶向穿膜纳米递药系统的研究

Combination of chemotherapy and gene therapy is considered to have broad prospects for tumor therapy and MDR reversal, and it is critical for the combination therapy to construct tumor-cell targeting nanoscale drug delivery system that can simultaneously carry chemotherapy drugs and therapeutic genes. Design ideas as follow are firstly proposed in this project: iRGD-reconstituted high density lipoprotein (iRGD-rHDL) as tumor-cell targeting biomimetic nanovector is prepared by covalent modification of iRGD peptide in the surface of rHDL; The model drug group of combination therapy (Doxorubicin, p53 gene plasmid and siRNA-MDR-1) is loaded in the iRGD-rHDL by three carrying technologies such as physical embedding, DNA compressing and lipid anchoring, to build an anti-tumor synergistic action mechanism based on of chemotherapy, gene replacement and silent therapy; Finally, the "trinity" type nanoscale drug delivery system of tumor MDR reversal for the same tumor cell is constructed by using iRGD peptide with tumor-cell intelligent targeting and penetrating. The system is of high efficiency and low toxicity, tumor targeting and high efficient carrying, and can reverse tumor MDR by the multi-mechanisms. It not only provides a new design pattern for combination of tumor chemotherapy and gene therapy, but also provides a new solution for the identical target site and co-delivery of chemotherapy drugs and therapeutic genes. This project will focus on construction, quality assessment, in vitro and in vivo antitumor activity and effect and mechanism of tumor MDR reversal of the system.

化疗联合基因治疗被认为对肿瘤治疗和MDR逆转前景广阔，构建可同时运载化疗药与治疗基因的肿瘤细胞靶向纳米递药系统是实现该联合治疗的关键。本项目首创设计将iRGD肽表面共价修饰的重组高密度脂蛋白（iRGD-rHDL）作为肿瘤细胞靶向仿生纳米载体，采用三种技术（物理包埋、DNA压缩、脂质锚定）运载联合治疗模型药物组（阿霉素、p53基因质粒和siRNA-MDR-1），建立一种基于化疗、基因替代与沉默疗法的抗肿瘤协同作用机制，借助iRGD肽对肿瘤细胞的智能靶向和穿膜性，构建针对同一肿瘤细胞的"三位一体"式逆转肿瘤MDR纳米递药系统。该系统具有高效低毒、肿瘤靶向、高效运载、多机制逆转肿瘤MDR等特点，为肿瘤化疗联合基因治疗提供一种全新设计模式，也为化疗药与治疗基因的同靶区、共传输提供一种全新解决方案。项目将重点围绕该系统的构建、质量评价、体内外抗肿瘤作用、逆转肿瘤MDR效果及机制等展开研究。

化疗联合基因治疗被认为对肿瘤治疗和MDR 逆转前景广阔，构建可同时运载化疗药与治疗基因的肿瘤细胞靶向纳米递药系统是实现该联合治疗的关键。本项目首先构建了基于重组高密度脂蛋白（rHDL）的紫杉醇（PTX）/p53和PTX/HZ08两个共传输系统，在此基础上，设计并构建了iRGD 肽修饰重组高密度脂蛋白（iRGD-rHDL）介导的多种药物（PTX、p53 基因质粒和HZ08）靶向递送系统：阳离子脂质DODAB通过静电作用可有效压缩p53基因质粒（pEGFP-p53）形成疏水纳米粒，将其有效地整合入rHDL的疏水核心；采用薄膜分散法制备Lipos/(PTX+HZ08+p53)纳米粒，将iRGD-rHDL与其共孵育，得到iRGD-rHDL/(PTX+HZ08+p53) 纳米粒，该纳米粒粒径在120 nm左右、电位为-20 mV。iRGD-rHDL/(PTX+HZ08+p53) 纳米递药系统的药物载体基本无细胞毒性，且该纳米粒对体外MCF-7/PTX细胞表现出很强的增殖抑制活性，体内研究中也表现出良好的肿瘤靶向性、体内抗肿瘤活性和逆转多药耐药效果。该研究借助iRGD 肽对肿瘤细胞的智能靶向和穿膜性，构建针对同一肿瘤细胞的"三位一体"式逆转肿瘤MDR 纳米递药系统。该系统具有肿瘤靶向、高效运载、高效低毒、多机制逆转肿瘤MDR 等特点，且构建该系统的载体材料具有生物相容性和生物可降解性，因此该项研究技术必将具有广阔的临床应用前景。本项目已完成预期研究任务，在国内外核心期刊上发表论文25篇，其中SCI收载论文15篇，国内核心期刊论文10篇；获得省级奖励2项；培养博士研究生2名、硕士研究生5名。