基于微纳结构和电场多模块相耦合的3维微流控芯片循环肿瘤细胞检测研究

Circulating tumor cells (CTCs) are the cells which detached from the primay tumors and enter into the blood circulation, emerging as novel tumor biomarkers and providing unique information for the cancer patients. The detection and monitoring of CTCs, is useful for the prognosis, prediction of response to therapy, or guiding clinical decision making for the patients with localized or metastatic disease, such as breast, prostate and colorectal cancers. Since the CTCs are detached from the primary tumors, they can represent an enrichment of biomarkers, which offer a distinct advantage over single biomarker detected by the conventional method, such as plasma DNA. Recently, different technologies have been developed for capturing and releasing CTCs based on different strategies, such as the surface specific antigen, the size of cells and the electrical properties. Some of these technologies have been successfully used for CTCs capturing and releasing from patients peripheral blood. However, challenges remain in improving CTCs capture and release efficiency, purity, activity, and so on, which is due to the very low quantity of CTCs in normal blood cells. .In our research proposal, we will take advantage of the inherent size, surface nanostructure, electric characterization of CTCs, to fabricate a 3 dimensional circulating tumor cells detection platform by coupling multi-module in microfluidic chips, to achieve highly capture efficiency and purity. We will improve the captured CTCs purity through the electric field integrated in the chip. We have demonstrated highly CTCs capturing on different nanomaterials, such as TiO2 nanofiber or nanoparticles, magnetic particles, due to the enhanced topographic interactions between the nano materials and cell surface componets. These preliminary results constitute a solid foundation for realization of our proposed research. This is very important for the sequential molecular analysis, in situ culture, drug screen of CTCs. On the other hand, based on our detection platform, we can investigate the role of CTCs in cancer metastasis, therapy and prognosis in the future.

循环肿瘤细胞（CTCs）是从原发肿瘤病灶上进入外周血循环系统中的细胞，在癌症转移及复发中具有重要的作用，可作为生物标志物来衡量癌症的发展状态以及癌症病人治疗后的效果。循环肿瘤细胞检测技术正成为一种可靠的、非侵入的、低成本的新型癌症诊断技术。为了充分发挥CTCs在癌症转移和治疗中的作用，CTCs的检测技术还存在着很大挑战，如何获得更高纯度的CTCs，如何提高全血样品中CTCs的捕获效率。.基于此，本项目将从CTCs本身细胞特性出发，借助癌细胞本身尺寸大小以及细胞表面的纳米结构、表面电荷三大特性，构筑多模块相耦合的3维循环肿瘤细胞微流控芯片检测平台，实现对CTCs的高效、快速、准确捕获。将电场耦合在检测平台，提高检测平台对全血样品中CTCs的捕获纯度和能力。本项目的顺利实施对CTCs的下游研究非常重要，比如：CTCs的高活性原位培养,癌症转移，提高预后时间等方面。

恶性肿瘤是威胁人类健康的杀手之一。肿瘤转移是治疗癌症的最大阻碍。如何实现对癌症转移的实时监测及早期发现，对于肿瘤或癌症的治疗非常重要。血液里富含营养物质，通过血液循环系统，是癌症转移的主要途径。如何实现对血液循环系统中的癌细胞实现快速和准确检测，对于癌症早期防治非常重要。循环肿瘤细胞的检测也正成为癌症检测及治疗的标志物之一。然而，从大量的正常的血细胞中检测出数量稀少的循环肿瘤细胞，还具有很大挑战。以循环肿瘤细胞为研究对象，根据细胞所具有的尺寸特性及细胞膜表面纳米结构特性和膜电位特性，本项目利用微米/纳米复合结构及微流控芯片，研究癌细胞的捕获及细胞形态。利用集成PDMS微米柱及鱼骨结构的微流控芯片，结合抗原抗体特异性反应，可以获得对癌细胞的高效捕获，捕获效率达到90%。我们借助电化学传感器检测技术，借助微米柱及氧化石墨烯，实现了对癌细胞的灵敏检测，检测限达到每毫升10个。此外，我们利用PDMS微米柱和PLGA纳米线的复合3维结构，研究了这种立体的细胞捕获技术，与常规的2维平面纳米结构捕获技术相比，具有更多的细胞捕获位点。癌细胞在转移的过程中，细胞形态与所处的微环境有很大关系。从原癌灶脱离，进入血液循环系统，再从血液循环系统穿越血管壁进入到其它组织，细胞形态及细胞核也会相应发生变化。在本项目中，根据细胞的微米尺寸特性及细胞膜表面纳米尺寸特性，我们利用两步水热反应法制备了仿生微米/纳米复合介观界面，并研究了癌细胞在此界面上的细胞形态及细胞核的变化。在此介观界面上，癌细胞的细胞面积变大，细胞膜表面更光滑。同时，细胞核也随着微米孔洞尺寸的增大发生剧烈变形，但不会影响细胞的有丝分裂。本项目围绕微米/纳米复合结构，利用癌细胞所具有的多重特性，研究了癌细胞的捕获及细胞形态，为后期研究癌细胞的早期转移提供基础。