核酸功能化聚吡咯纳米体系在肿瘤细胞靶向成像与治疗中的研究

Development of functional nanosystems for early accurate diagnosis, targeted therapy, and cell apoptosis imaging in tumors is an important research direction in translational nanomedicine, which is of great significance for cancer treatment. However, current theranostic nanoparticles for mRNA imaging have some disadvantages, such as lack of cellular targeting and specific intracellular response. In this project, a series of nanosystems will be developed for molecular sensing and therapy in living cells, based on the fluorophore-labeled nucleic acid and polypyrrole (PPy) nanoparticles. Firstly, a multicolor fluorescence nanoprobe based on the fluorophore-labeled nucleic acid functionalized PPy nanoparticles will be developed. This nanoprobe can simultaneously detect three intracellular tumor-related mRNAs, which will identify the tumor cells at the cellular level in an early stage. Subsequently, a PPy nanoagent combined the ZIF-8 and DNAzyme will be fabricated. In the presence of intracellular acid pH value, ZIF-8 will be degraded to Zn2+ ions, which serve as cofactors of DNAzyme for targeted gene silencing. In addition, a nanosensor based on the aptamer, peptide probe and PPy NPs will be developed for real-time fluorescence imaging of cell apoptosis. This developed nanosensor may provide an invaluable platform for apoptotic studies and the possibility for cell-based screening of apoptosis-inducing drugs. This study is expected to provide an important reference for the early diagnosis and treatment of cancer.

发展功能纳米体系用于肿瘤的早期精确诊断、靶向治疗以及肿瘤细胞凋亡成像是当前纳米转化医学的重要研究方向，对癌症治疗具有重要意义。针对当前应用于mRNA成像和肿瘤治疗的纳米诊疗试剂缺少同时细胞靶向及细胞内特异响应的功能的不足，本项目拟构建一种核酸功能化的聚吡咯纳米体系，用于肿瘤细胞内多种mRNA的靶向荧光成像，以实现肿瘤细胞的早期精确检测；在此基础上，聚吡咯纳米体系结合金属有机框架结构材料用于构建基于DNAzyme响应的基因沉默治疗方法，以降低对正常细胞的杀伤作用，实现肿瘤细胞的特异性靶向治疗；此外，为进一步研究肿瘤治疗过程中的细胞凋亡现象，本项目拟构建基于聚吡咯纳米体系的细胞凋亡荧光成像探针，以实现细胞色素c和caspase-3的实时成像，用于研究肿瘤细胞凋亡中相关分子的变化，加深对细胞凋亡过程的理解及药物开发的优化。本研究有望为癌症的早期诊断、治疗及药物开发提供重要的参考价值。

发展功能纳米体系用于肿瘤细胞的精准诊断、靶向治疗及肿瘤细胞凋亡成像是当前纳米生物医学的重要研究方向，对于癌症的精准诊疗具有重要意义。本项目以设计和构建肿瘤细胞成像和治疗的功能纳米材料，用于实现肿瘤特异响应的诊疗及细胞凋亡成像为目标，完成了几种功能纳米探针的开发及其生物医学应用。具体研究成果包括：（1）构建了一种靶向肿瘤细胞的纳米复合物用于肿瘤特异信使RNA响应的光动力和化疗联合治疗；（2）构建了一种基于核酸和多肽功能化的金纳米颗粒基荧光纳米探针，实现细胞凋亡中两种关键生物标志物的灵敏、特异检测和成像；（3）构建了一种含有乏氧响应基团的共轭聚合物纳米颗粒用于递送化疗药物喜树碱和光敏剂Ce6，实现光动力治疗和化疗治疗；（4）构建了一种核酸修饰的聚多巴胺包裹金纳米颗粒探针用于肿瘤细胞的miRNA成像和增强光热治疗。（5）获得了一种检测生物样品中谷胱甘肽的荧光检测方法，实现细胞内和血清中谷胱甘肽的特异、灵敏、简单检测；（6）获得了一种检测血清中碱性磷酸酶的荧光检测方法，实现碱性磷酸酶的灵敏、特异、低成本分析检测。本项目的完成在功能纳米材料应用于肿瘤靶向治疗和细胞凋亡成像等方面具有重要的参考意义和应用价值。（7）构建一种基于聚合物点和多巴胺纳米体系的生物样品中谷胱甘肽荧光传感分析方法，实现血清和细胞裂解液中谷胱甘肽的灵敏、特异检测。