基于目标物循环放大的核酸－嵌段共聚物复合纳米探针的活细胞成像传感新方法研究

Many hereditary diseases and cancer are closely related to the change of specific genetic information or the invasion of exogenous gene. Gene diagnosis by messenger RNA analysis could realize many information, such as gene expression associated with major diseases, the changes of information and gene expression induced by the drug effect in the cell, and make judgement and evaluation to the drug target spot and effect. However, major challenges and problems of using nanoprobes for mRNAs real-time, in situ living cell fluoresecence imaging are their biocompatibility, the efficiency for delivery into cells, the sensitivity for target detection. Aiming at the above problems, this project is to develop strategies on nucleic acid－amphiphilic block copolymer nanocomposite with target cyclic amplifying technique for the fluorescent imaging of mRNA in living cells. The amphiphilic block copolymers exhibits extraordinary properties in biocompatibility, controllable synthesis in chemical structure and photostable. Based on crosslinking of nucleic acid probes with amphiphilic block copolymer, combined with hairpin DNA cascade amplifier (CHA), this project is to explore mRNA real time, in situ, visualization living cell fluoresecence imaging and biosensing with high sensitivity and selectivity, and provide an invaluable platform for related biomedical research, clinical diagnosis and drug screening.

许多遗传性疾病和癌症的发生都与特定基因信息的改变或外源基因的入侵密切相关，通过信使RNA分析进行基因诊断，可了解重要疾病相关基因的表达、信息的改变情况以及药物作用所导致的细胞内基因表达的变化情况，从而对药物的靶点和效果做出判断和评价。但是，利用纳米探针实现mRNA实时、原位活细胞荧光成像仍面临许多问题和挑战：如探针的生物相容性、核酸输送效率、检测灵敏度等。针对上述问题，本项目拟发展一类基于目标物循环放大的核酸－嵌段共聚物复合纳米探针，用于活细胞内mRNA的成像分析。由于两亲性嵌段共聚物在生物相容性、化学结构可控合成、光学等方面有着非常优异的性质，本项目拟将核酸探针共价交联在两亲性嵌段共聚物上，结合发夹DNA级联反应（CHA）信号放大技术，探索发展mRNA实时、原位、可视化、高灵敏、高选择性的活细胞高灵敏成像生物传感新方法，并为相关的生物医学研究、临床诊断、药物筛选提供有效技术平台。

细胞内RNA的检测与分析对了解疾病的发生发展以及相关药物的研发与筛选具有重要意义。发展活细胞内RNA的实时、原位、高灵敏荧光成像分析仍然是一项挑战性任务。本项目利用一系列新型纳米材料的独特物理化学性质，围绕“基于目标物循环放大的核酸－嵌段共聚物复合纳米探针的活细胞成像传感新方法研究”，结合功能核酸信号放大策略，在开发生物相容性好、功能核酸输送效率高的功能纳米探针用于活细胞内RNA的高灵敏荧光成像分析以及其他重要生物分子的分析检测等方面开展了较系统深入的研究工作。发表标注基金资助SCI源刊论文18篇，其中第一作者1篇，通讯作者11篇。在第一或通讯作者论文中影响因子>5.0的论文9篇，包括The Journal of the American Chemical Society 1篇，Analytical Chemistry 2篇，Chemical Communications 3篇，Nanoscale 2篇，Biosensors and Bioelectronics 1篇。同时，项目组培养了5名硕士生，参与培养了4名博士生，圆满完成了既定目标和任务。