基于纳米悬臂梁阵列的单细胞力学特性生物传感器研究

A growing body of evidence suggests that the properties of cellular mechanical forces plays a crucial role in the regulation of many cellular processes, however, due to the restrictions in the method of loading sample and measurement tools, there still exist some shortcomings for the cell traction forces biosensor, such as the low mechanical sensitivity and poor resolution. In this project, we plan to develop a novel single cell traction forces nanopillars matrix biosensor based on the transduction mechanism between cell biomechanical and mechanical force. As an initial step, We research the micro-mechanism of the interactions between cell and extracellular matrix (ECM),then establish a physical model of nanopillars matrix under the external force. Further, the key parameters of nanopillars are optimized by modeling, simulation and calculation analysis. In order to solve the problem of mechanical stability, which is caused by the high aspect ratio of nanopillars, the nanoimprint lithography and backside exposure technique are introduced. To eliminate cell-cell interaction, micro contact printing (μCP) is carried out to transfer the biomolecular to the top of nanopillars, and the single cell arrays can be obtained successfully after cell culture on the nanopillars. The characteristic of high sensitivity for the fabricated biosensor is proved by the experiments of single cell traction force, which is used by human cells. In conclusion, this project aims to reveal the transduction mechanism between biomechanical and mechanical force, which is expected to provide a solid theoretical foundation and strong technical support for the biosensors detection of pathogenesis in human cells.

细胞力学特性是细胞与分子生物力学研究的最关键问题，由于受细胞实验加载方法和测量手段的影响，目前基于细胞牵引力的生物传感器仍然存在力学灵敏度和分辨率相对比较低的问题。本项目拟从研究纳米悬臂梁阵列生物传感器的细胞生物力-机械力的转导机制出发，开展细胞与材料表面相互作用的微观机制的研究，建立外力作用下纳米悬臂梁结构的力学特性响应物理模型；通过建模仿真与计算分析，实现纳米悬臂梁关键参数的最优化结构设计；提出且利用先进的纳米压印技术和背曝光工艺，解决悬臂梁临界深宽比而造成的机械稳定性问题；开展纳米软印刷生物分子图案化技术的研究，消除相邻细胞间的相互影响，实现单细胞阵列化；针对人体细胞进行细胞力学特性实验，验证并实现基于纳米悬臂梁阵列的单细胞力学特性生物传感器的高灵敏度特性。本项目旨在揭示纳米悬臂梁生物传感器的细胞生物力-机械力的转导机理，为生物传感器在人体细胞发病机制检测的突破性进展奠定理论基础和

本项目开展了以制备高灵敏悬臂梁阵列生物力学转换器为目标，以干细胞和肿瘤细胞为主要对象，探索了细胞在粘附过程中的生物力-机械力的转导生物机制。利用紫外纳米压印和光刻技术制备出微/纳复合结构，研究了细胞在微/纳复合结构基底表面的微观粘附机制；采用微接触印刷技术实现了纳米尺度内蛋白结构的图案化转移，形成了单细胞阵列结构。同时，结合背曝光和热压印技术制备出不同尺寸结构的悬臂梁阵列，研究细胞在不同环境条件下与纳米悬臂梁阵列的相互作用，运用荧光技术对细胞与纳米悬臂梁作用的全场应变和运动规律进行监测；在单细胞层面上实现对细胞牵引力的精确测量，为生物传感器在人体疾病的早期预测提供实验数据支持。项目共发表论文10余篇，其中SCI论文10篇；获山西省2012年科学技术自然科学类三等奖1项。