基于肿瘤细胞和肿瘤相关巨噬细胞构建协同抗肿瘤效应的氧化石墨烯纳米递药体系

This project is to develop a multifunctional nano-drug delivery system targeting both tumor cells and tumor associated macrophages (TAMs), in order to kill tumor cells and repolarize the phenotype of TAMs from M2 to M1. Nano-sized graphene oxide (nGO) is used to prepare two groups of nGO-PEI based nano-drugs. One is conjugated with folic acid (FA), loaded with anti-tumor drug (doxorubicin, Dox), for targeting cytotoxicity to tumor cells. The other one is conjugated with 1,2-dipalmitoyl-sn-glycero-3-phospho-L-serine (DPPS), loaded with miRNA-155, for targeting repolarization of TAMs. pH-sensitive charge-reversal PEG-DMMA is used to wrap the two nano-drugs to form nanocomplexes through electrostatic interaction. While at the tumor environment, the DMMA was hydrolyzed, leading to the charge reversal and exposure of the two nano-drugs, thus realizing tumor cells and TAMs targeting respectively. The chemical construction, conjugating amount and drug loading are determined by nuclear magnetic resonance, infrared spectrum, etc. The ratio of nanocomplexes and pH-sensitive responsibility are studied by the particle size, surface charge and morphology. The cellular uptake and intracellular trafficking of nano-drugs are observed by confocal laser scanning microscopy (CLSM). In vivo imaging system is used to study the distribution and anticancer effect. Pharmacodynamics studies in vivo and in vitro will be performed to investigate the inhibition of the tumor growth and remodeling of immune environment, providing a new synergistic targeted strategy for tumor targeted nano-drug delivery system.

课题旨在构建肿瘤细胞和肿瘤相关巨噬细胞（TAMs）双重靶向的纳米递药体系，以期达到杀灭肿瘤细胞、重塑TAMs表型的目的。以氧化石墨烯（nGO）为原料，设计两组nGO-PEI纳米药物：一组连接FA，加载Dox，靶向并杀伤肿瘤细胞；另一组连接DPPS，加载miR-155，靶向并重塑TAMs。pH敏感电荷翻转型聚合物PEG-DMMA包裹两组纳米药物，形成目标纳米复合物。靶向肿瘤微环境，响应性释放两组纳米药物，分别特异性地靶向肿瘤细胞和TAMs。核磁、红外等表征纳米药物的结构、接枝率及载药量等；粒径、表面电荷等变化研究纳米复合物的配比，以及与pH值响应之间的关系；激光共聚焦荧光显微法、活体成像系统检测纳米复合物与肿瘤细胞和TAMs的相互作用及体内分布；体内外药效学验证其双重靶向对抑制肿瘤生长与重塑免疫环境的作用，为肿瘤靶向递药体系提供新的协同靶向设计策略。

氧化锌纳米粒（ZnO NPs）被开发用作纳米药物和药物载体，用于治疗各种疾病，包括传染病和癌症等。然而，由于生物相容性低、体内半衰期短和潜在的毒性，ZnO NPs相关研究主要用于体外实验，可用于体内给药的有效且安全的ZnO NPs系统还很少被报道。本研究中，我们通过对ZnO纳米粒进行改性修饰，制备了一种pH与双酶重响应性ZnO纳米复合物，可用于抗肿瘤药物阿霉素体内靶向递送，同时克服肿瘤细胞MDR，提高药物抗肿瘤活性。将ZnO/DOX包裹在MMP2酶敏感的聚合物PEG-pp-PE形成的胶束核内，形成纳米复合物ZnO-DPPG/PEG-pp-PE/DOX，可以降低ZnO/DOX非特异作用，延长体内循环时间，并提高肿瘤靶向作用能力。细胞内摄和毒性实验表明ZnO/DOX能够有效克服肿瘤细胞MDR，促进药物入胞，胞内ZnO纳米粒响应酸性pH环境而溶解，释放出DOX，发挥抗肿瘤作用；耐药细胞三维多细胞球实验表明ZnO/DOX可以将药物带入多细胞球内部，显著提高渗透性；ZnO-DPPG/DOX@PEG-pp-PE体内外抗MDR肿瘤活性实验表明该纳米复合物具有良好的杀伤肿瘤细胞和抑制肿瘤生长效果，且无明显的毒副作用。这些结果表明，该纳米复合物是一种很有前景的针对MDR肿瘤治疗的药物递送系统。