基于信号放大技术的表面增强拉曼成像分析法用于肿瘤细胞检测及单细胞分析

Cancer is a leading cause of death worldwide and accounts for several millions of deaths every year. The survival of cancer patients is strongly associated with the stage of the tumor at the time of diagnosis. Identifying the cancer at the cellular level in an early stage before metastasis holds great promise for increasing the survival of cancer patients. Nowadays, SERS has emerged as a highly specific, rapid and sensitive tool for biological analysis. It can provide molecular-level identification of sample, multiplexed detection capability, easy operation without complicated sample preparation, nondestructive detection in a wide variety of matrices. In this project, based on the aptamer recongnition and DNA multiple cycles amplification, a series of novel SERS signal amplification methods will be developed for cancer cells imaging and single cell imaging analysis. Because of the sensitivity, simplicity, rapidity and low-cost, these methods could be easily used for biological sample imaging analysis. The proposed methods may offer new approaches for sensitive and selective tumor cell imaging for early cancer diagnosis.

本项目拟采用表面增强拉曼成像技术，以肿瘤细胞为研究对象，基于核酸适体与细胞表面蛋白及细胞内活性物质的特异性结合作用，研制多功能拉曼分子成像纳米复合探针，结合信号放大技术，设计细胞以及亚细胞水平的分子成像系统。建立肿瘤细胞的高灵敏高选择性表面增强拉曼成像分析新方法、新技术，实现对复杂生物体系中微量或痕量肿瘤细胞的检测，构建单细胞表面增强拉曼成像技术平台，为癌症早期诊断与致癌分子机制研究提供灵敏、快速、便捷的新工具。

本项目开展了肿瘤细胞以及相关活性分子的表面增强拉曼光谱(Surface enhanced Raman scattering, SERS)检测及成像分析研究。通过制备新型多功能纳米探针，结合信号放大技术，构建了双前体自产生聚合酶剪切循环、无酶DNA分子机器信号放大方法，实现了对ATP、血小板衍生因子PDGF-BB、癌症标记物miRNA-203的高灵敏高选择性检测，并进一步设计了不对称信号放大成像分析方法和SERS比例检测，可以原位示踪细胞内的探针分布，对癌细胞中的多种存在水平差异较大的miRNAs进行表面增强拉曼成像分析和定量检测。.总之，本项目圆满完成了肿瘤细胞及细胞内部活性物质的表面增强拉曼光谱检测及成像分析研究，为拉曼光谱在生物学及临床医学等领域的应用提供了重要的参考和依据，也为进一步开展新的课题研究打下坚实的基础。