兰州大学机构库 >土木工程与力学学院
基于原子力显微镜的细胞力学性质研究
Alternative TitleStudy of mechanical properties of cells with atomic force microscopy
段文立
Thesis Advisor王记增
2015-05-28
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name硕士
KeywordAFM 细胞 癌症 弹性/粘弹性 接触模型 杨氏模量
Abstract本文针对癌细胞与正常细胞在力学性质上的差异(以肝细胞为例)主要展开了以下的研究:首先,研究了基于接触力学的分层弹性介质弹性系数的预测问题。将细胞考虑成双层弹性结构,分别讨论双层结构的硬度和厚度对细胞等效杨氏模量的影响。其次,提出了利用原子力显微镜测量细胞力学性质时新的标定方法。该方法对线弹性Hertz接触公式进行坐标平移,得到了不依赖于接触点的压痕曲线所对应细胞的力学性质。 最后,利用原子力显微镜对正常肝细胞CHO和低侵袭性的肝癌细胞HEP G2的力学性质进行实验研究。1、对两种细胞不同加载速率下的力学性质进行比较。随着加载速率的增大,细胞变形减小。癌细胞在相同的载荷和加载速率的情形下变形明显比正常细胞要大。基于修正的Hertz接触结果,各种加载速率下癌细胞的两阶段杨氏模量都比正常细胞的要小。2、对HEP G2细胞不同部位的力学性质进行了比较。发现肝癌细胞的靠近细胞边缘和细胞核部分的硬度较大。 3、利用线性粘弹性模型,分别对CHO和HEP G2细胞不同加载速率的压痕曲线分析得到对应的最优解。虽然粘弹性的模型不同,但是均难以同时描述不同细胞、不同加载速率下的压痕曲线。这就说明不同的加载率下细胞的杨氏模量和粘性系数均发生了变化。
Other AbstractThis article focus on the difference between the abnormal and cancer cells in mechanical properties, CHO and HEP G2 for examples. Firstly, the inversion problem of layered elastic medium is studied based on the contact mechanics. Considering the young’s modulus of the large indentation depth is the comprehensive effect of each part of the cell, we will consider the cell as a double-layer structure. Secondly, this article development a new calibration method to analysis the mechanical properties of cells from the force-depth curve aiming at the uncertain of the contact point in the experiment. Here we no longer care about the location of the contact point, but though the coordinate translation of the linear elastic Hertz contact formula get the hardness of the specific part of cell indentation curve. Finally, we choose the health liver cells CHO and lower infectious cancerous liver cells HEP G2 to the experimental research with AFM.1. Compare the mechanical properties with two kinds of cells in different loading rates. The deformation of cells will decrease, with the increase of loading rate. When the loading rate increase, the creep of the cell will decrease which lead to the deformation of the cells decrease. The deformation of the cancerous cells is larger than the normal ones with the same force and loading rate. 2. Compare the mechanical properties in different parts of HEP G2 cells. We found that the young’s modulus of the edge and the nucleus part of the liver cancerous cell is larger. 3. Fitting the CHO and HEP G2 force-depth curve in different loading rate with a linear viscoelastic model. Although the viscoelastic model is different , none of them can describe the force-depth curve with different cells and different loading rate.
URL查看原文
Language中文
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/226241
Collection土木工程与力学学院
Recommended Citation
GB/T 7714
段文立. 基于原子力显微镜的细胞力学性质研究[D]. 兰州. 兰州大学,2015.
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