用于活体肿瘤端粒酶高灵敏定量检测的纳米探针的设计、合成及应用

Telomerase, an enzyme that repairs and elongates telomeres, is closely related to the division and proliferation of cancer cells. It is overexpressed in cancer cells and has high activity, and can be used as a marker for the detection and diagnosis of cancer. Recently, the nanoprobes used for detecting telomerase are mainly based on the design of gold nanoparticles and DNA molecules via fluorescence resonance energy transfer (FRET). However, telomerase detection is mainly at the cellular level, and in vivo detection is difficult to achieve. This is mainly because the excitation and emission wavelengths of the nanoprobe and fluorescence dyes are located in the visible region, which have poor tissue penetrating ability. Furthermore, the obstacle of biological spontaneous background fluorescence interference limits the in vivo applications severely. In addition, the quantitative detection of telomerase in vivo is also a big problem needed to be solved urgently. In this project, we design nanoprobes by employing gold nanoparticles, upconversion nanomaterials and DNA molecules to construct photoacoustic nanoprobes and near-infrared fluorescent nanoprobes, which can realize the quantitative detection and imaging of telomerase with highly sensitivity. And we will study the expression level of telomerase at different division stages. In addition, further exploration of the relationship between telomerase expression and cancer cell metastasis and related pathways will be conducted. It will provide new methods and new tools to better reveal the role of telomerase in tumors, which have great potential for clinical applications and is of great significance.

端粒酶，是一种能够修复延长端粒的酶，与癌细胞的分裂增殖密切相关。它在癌细胞中过量表达且具有高活性，可作为癌症标志物，用于癌症的检测和诊断。目前用于检测端粒酶的纳米探针主要基于金纳米颗粒及DNA分子，通过荧光共振能量转移原理实现检测，但其主要集中在细胞水平，活体水平上的检测难以实现。这主要是因为纳米探针的激发和发射波长位于可见光区，其组织穿透能力差，且生物自发背景荧光干扰严重。其次，活体端粒酶定量检测也是目前亟待解决的难题。本项目基于金、上转换纳米材料及DNA分子，利用光声信号及近红外光较强的组织穿透能力，设计合成用于活体端粒酶检测的光声纳米探针及近红外纳米比率荧光探针，实现活体中端粒酶的高灵敏定量检测。同时，进一步探究肿瘤不同时期端粒酶表达水平、端粒酶与癌细胞转移侵袭能力的关系及相关通路。该研究为更好地揭示端粒酶在肿瘤中的作用提供了新方法和新工具，具有极大的临床应用潜力及重要意义。

发展高灵敏传感新策略，实现活体肿瘤内端粒酶活性高灵敏、高特异性检测，为癌症的精确检测、精准医疗和预后评估等提供技术和方法支持，具有重要的理论和实际意义。本工作发展了活体端粒酶活性检测新探针和新方法，基于DNA互补配对原理诱导金纳米颗粒聚集，首次构建了光声检测端粒酶活性新策略，设计合成双金纳米探针，实现活体肿瘤端粒酶特异性光声成像检测；利用上转换纳米材料多重发射的优点，结合金纳米颗粒的对特定波长荧光的淬灭性质，设计合成金-上转换卫星结构纳米探针，实现980 nm近红外光激发下的端粒酶比率检测；基于巨噬细胞可以穿透血脑屏障并对渗透排斥免疫微环境响应，设计合成了仿生探针，构建了脑胶质瘤浸润边界术前界定新方法和新策略，同时该探针能很好识别微小的卫星灶，为脑肿瘤手术切除提供有效指导。在国家自然基金的资助下，在Chemical Communications、ACS Applied Materials&Interfaces学术期刊上发表 SCI 收录论文3篇，影响因子大于10.0的1篇，大于6.0的3篇。指导硕士研究生毕业1人，在读4人。项目执行期间，项目负责人获批山东省自然科学基金优秀青年基金一项，获2020年度山东省自然科学二等奖（第三位）。