基于力学效应的微悬臂梁传感技术在细胞活性监测上的研究

Looking for anticancer drug with high selectivity and small side effect is always one of the focus in the study of antitumor drugs. In the early of new era, a microcantilever sensor which is based on mechanical effect was developed. The principle of conventional microcantilever is based on the change of surface stress or the shift of resonance frequency. In our conventional research, we found that, in addition to this change and shift, the presence of living cell on microcantilever caused an obvious fluctuation of microcantilever, and when the activity was increased (or decreased), the fluctuation was also increased (or decreased). So, we can detect the cell activity in real-time and on-line using this new phenomena. Based on the new principle, this project prepares to detect the activity of cancer cells and the changes of the activity after treatment of different drugs to achieve antitumor drug screening. Through controlling the cell metabolism, we study the relation between the strength of the cell metabolism and the fluctuation. And for different cytoskeletal proteins of the cell, we add corresponding drug to suppress them, and then monitor the change (distribution, dynamic property and content) of proteins and the variation of the fluctuation to study the intrinsic mechanism of internal relation between the microcantilever fluctuation and the activity of cells.

寻找选择性高、毒副作用小的抗癌药一直是抗肿瘤新药研究的重点之一。本世纪初发展了一种基于力学效应的微悬臂梁生化传感技术，传统的微梁传感都是基于表面应力的变化或者共振频率的漂移来实现检测。除此之外，我们还发现活细胞的存在导致了微梁明显的涨落，当细胞的活性在外界条件的改变下增强或者减弱时微梁的涨落也分别相应的增大和减少。因此，可以通过将细胞吸附在微梁表面，利用这一现象实现对细胞的活性进行实时在线监测。本项目拟利用这一新的现象来实现对癌细胞活性的实时监测，并检测其在不同药物作用下活性的变化情况，从而实现微悬传感技术在细胞层次对抗癌药物的筛选。调控细胞新陈代谢的强弱，研究代谢的强弱和细胞活性与微梁涨落大小的关系。对细胞骨架蛋白进行标记，监测它们在相应的抑制药物作用下的变化情况（分布、动态性能和量的变化）以及微梁涨落的改变，从而研究微梁的涨落和细胞活性间内在联系的内在机理。

细胞活性是判断体外培养细胞在某些条件下是否能正常生长的重要指标，是体外筛选抗肿瘤药物和临床肿瘤药敏试验的重要方法之一。目前常用的评价细胞活性的方法都比较贵或无法量化细胞的活性而只能区分活细胞和死细胞。另外，这些方法需要荧光或放射性物质标记，过程很繁琐。因此，发展非标记、非侵入、经济、高效的方法来定量检测细胞的活性及其在药物作用下的变化情况对药物筛选尤其是对杀灭癌细胞的抗癌药物的筛选有着重要的意义。.本项目在利用传统的基于表面应力效应的微悬臂梁传感技术对细胞进行检测时发现，活细胞除了能引起微悬臂梁的静态变形之外还产生了微纳尺度的机械震颤这一全新现象，同时发现机械震颤的幅度与细胞的活性息息相关。基于这一全新现象，本项目提出了从微机械力的角度对细胞的活性进行表征，并通过计算机械震颤曲线的方差实现了对细胞活性的定量检测。成功将这种全新的模式应用于抗癌药物的实时在线筛选；同时，利用这一全新技术成功实现了对精子活力的快速检测，提出了从力学的角度去评价精子的活力，为生殖医学研究和男性不育治疗提供了一个全新的角度。