受体介导的碳点荧光探针的构筑及细胞成像研究

Cancer（malignant tumor）is a serious threat to human health and life. The diagnosis of tumor in the early stage is a challenge issue. It is very important to search for the valid method of early tumor diagnosis. Fluorescent carbon dots (CDs) have become good candidate of fluorescent labels in biological and medical fields due to its many attractive features such as ultra-small size, good biocompatibility and excellent photo-stability. The development of CDs fluorescent probes with targeting imaging in cancer cells is of significance. The project focuses on the design and synthesis of a series of CDs with good biocompatibility and photoluminescence properties based on different sources of carbon. Some importantly active molecules with targeting recognition to cancer cell such as transferrin and CD20 and 4-anti-claudin4 etc. are conjugated to the surface of CDs by chemical reaction for functional modification. Some specific receptors are excessively expressed on the surface of tumor cells. These specific receptors have a specificity that they can bind to ligands selectively by utilizing the specificity, the receptor mediated CDs fluorescent probes are constructed. The related fluorescence behaviors of probes are explored and cytotoxicity of probes are evaluated. The as –prepared CDs are further applied for targeting imaging and detection of cancer cells.

癌症严重威胁人类健康和生命，肿瘤的早期诊断面临严峻的挑战，寻找有效的癌症早期诊断方法十分重要。荧光碳点具有超小的尺寸、良好的生物相容性和稳定的发光性质，已成为生物、医学领域荧光标记物的良好选择，发展靶向癌细胞成像功能的碳点荧光探针不仅具有理论意义且有潜在的应用价值。本项目拟选择不同碳源材料，设计合成一系列生物相容性好、发光性能优良的碳点，将一些重要的对肿瘤细胞有靶向识别功能的分子如转铁蛋白、CD20、反封闭蛋白等通过化学作用共价结合于碳点表面进行功能化，基于肿瘤细胞表面高表达的特异性受体可选择性地与相应的配体结合，构建受体介导的碳点荧光探针，探讨探针的发光特性，对其细胞毒性予以评价，并将其应用于癌细胞成像检测。

肿瘤的早期诊断面临严峻挑战，寻找有效的早期诊断方法十分必要。碳量子点具有尺寸小、生物相容性好和发光性能强等优点，为荧光探针的研究提供了新机遇。该项目研制了一系列多色荧光碳量子点和磷光碳量子点，运用现代分析方法对其进行表征，包括透射电镜、紫外、荧光、红外、光电子能谱、Zeta电势等，构建了受体介导的碳量子点荧光探针和癌症“诊疗一体化”碳量子点荧光探针，考察探针体系的发光特性、细胞毒性、稳定性等，研究其作用机理并应用于生物成像和肿瘤治疗。构筑了检测不同目标物的碳量子点荧光探针，用于药物、血样、尿样等实际样品的定量检测。项目取得了一些重要结果：（1）构筑了一系列受体介导的碳量子点荧光探针，建立了灵敏检测癌细胞的荧光传感新方法，成功实现荧光增强的癌细胞成像检测，为癌症早期诊断提供了理论基础；（2）构建了“诊疗一体化”碳量子点荧光探针，空心碳量子点的载药量高达35.43%，且具有pH可控释放的性能，深入探讨了该探针在细胞和活体内释放药物的机理，成功用于癌细胞靶向成像和活体抗肿瘤治疗，为“诊疗一体化”荧光探针的发展提供了新方法和新技术；（3）构筑了诸多检测细胞内信号离子、生物活性物质、细胞内pH等的高灵敏荧光分析方法，探讨了碳量子点与目标物相互作用的机理，为探针设计提供指导思想，拓宽了碳量子点在分析检测领域的应用范围；（4）研制了室温磷光碳量子点，在水溶液中具有664 ms的超长磷光寿命，探讨了碳量子点发射磷光的机制，为拓展碳量子点室温磷光材料应用于生物医学领域开拓了新思路。项目已发表SCI论文88篇，其中一区TOP论文22篇，代表性研究工作发表在Chemistry of Materials、Analytical Chemistry、ACS Applied Materials & Interfaces、Nanoscale等国际期刊上。发表于Analytical Chemistry的论文单篇引用115次，被评为ESI 1%高被引论文。本项目丰富了碳量子点的种类，拓宽了碳量子点的应用范围，构筑的靶向识别癌细胞的荧光探针为癌症早期诊断提供了新方法和新思路。项目的顺利实施将为促进碳量子点在生物医学领域的应用提供有效的支持。