红光响应双层三维微纳结构用于CTCs的高效捕获及无损释放研究

Detection of circulating tumor cells (CTCs) in peripheral blood is of utmost importance for cancer early diagnosis, monitoring drug efficacy and understanding tumor metastasis. However, isolating CTCs with high purity and high cell viability is still technically challenging due to their rare numbers (a few CTCs in billions of normal blood cells). Herein, we will develop a novel platform for highly efficient capture and non-invasive release of CTCs by integrating specific ligand-receptor binding with red-light-responsive host-guest interaction onto a 3D hetero-hierarchical micro/nanostructured substrate. We anticipate that the detecting platform holds such advantages: (1) 3D-hierarchical microsphere-polymer brush substrates, which can form multiple local topographic interactions with nanoscale components of the cellular surface, can achieve highly efficient capture of CTCs with the help of the strong affinity interactions between cells and various specific recognition molecules on polymer brushes. (2) Polymer brushes can provide the antifouling surface to resist nonspecific adhesion of other blood components and capture CTCs with high purity. (3) The cyclodextrin-azobenzene inclusion complex formed through host-guest interactions, which acts as a spacer connecting specific recognition molecules to polymer brushes, can be disassembled under red light irradiation due to photoisomerization of azobenzene derivative. Thus, the captured CTCs are gently released from the substrate without sacrificing the viability of the cells. This project will not only offer new methods and ideas for isolation and enrichment of CTCs, but also provide guidance for early cancer diagnosis, prognosis and personalized therapy.

循环肿瘤细胞（CTCs）的检测对癌症的早期诊断、疗效评估及转移机制研究等具有重要意义。从复杂的外周血中高效的分离痕量的CTCs（正常血细胞的十亿分之几）并保证细胞的高纯度和高活性依然面临挑战。本项目拟将双层三维微纳结构基底、配体-受体特异性识别与红光响应的主客体作用有机结合起来，发展一种CTCs高效捕获及其无损伤释放的分离平台。该平台具备以下特征：（1）双层三维微纳结构与CTCs形成多尺度结构匹配效应，结合高分子刷上多种识别配体与CTCs形成的免疫亲和作用可实现CTCs的高效捕获；（2）高分子刷良好的抗污性质有效抵抗血液其他成分的非特异性吸附，保证了捕获CTCs的高纯度；（3）作为桥连结构的偶氮苯衍生物-环糊精包结络合物在红光照射下发生自解离，实现CTCs无损伤释放保证其高活性。本课题的开展可为CTCs的分离富集提供一种新的方法，并为癌症的早期诊断、预后监控及个性化治疗提供参考和指导。

循环肿瘤细胞（CTCs）的检测对癌症的早期诊断、疗效评估及转移机制研究等具有重要意义。然而，由于其本身的稀有性和脆弱性，如何实现CTCs的高效率、高纯度和高活性分离仍然充满挑战。针对这些问题，本项目受自然界启发发展了多种能够高效捕获和友好释放CTCs的仿生检测分离平台，如仿细胞外基质和细胞膜结构的纳米纤维膜、仿章鱼结构和功能的磁性荧光纳米球、仿肿瘤微环境的三维高分子纤维网络等。这些平台具备以下特征：（1）双层三维仿生微纳结构与CTCs形成多尺度结构匹配效应，结合识别分子对CTCs的特异性亲和作用实现了CTCs的高效率捕获（>88%）；（2）检测基底良好的抗污性质有效抵抗了血液中其他成分的非特异性吸附，保证了捕获细胞的高纯度（>91%）；（3）在红光、pH、三磷酸腺苷、谷胱甘肽等多种生物友好刺激下分离平台发生解体，实现了捕获细胞的高效率释放（>94%）并保证了细胞的高活性（>93%）。此外，这些分离平台还具有一定的临床应用潜力，能够成功从54例癌症病人外周血中捕获到CTCs，而从14例正常人的外周血中不能检测到CTCs。本项目的完成为CTCs的高效分离富集提供了新方法，并为癌症的早期诊断、预后评估及个性化治疗提供了新思路。本项目已完成了预定的研究目标，在基金资助下共发表项目号（51903214）标注的学术论文6篇（其中3篇影响因子>10.0），申请中国发明专利3项（其中2项已授权），培养硕士研究生4名。