Test Methods On Nano-mechanical Properties Of Cancer Cells

As the number one killer of human health in the current age, cancer is concerned widely in the medical profession. Currently, the early diagnosis and treatment of cancer are mainly depended on tissue biopsies, chemotherapy and radiotherapy, and other macro-method, these methods have certain limitations and uncertainties. In this study, in order to reveal the mechanism of the cancer lesions, the study on the cancer cells in nano-level is carried out, which provide a new way for the early diagnosis and treatment of cancer. In this paper, various micro-characteristics of the cancer cells are analysised and researched from two aspects of cell morphology and mechanical physical characteristics by the atomic force microscope nano-testing system and other advanced test equipments.Taking mean roughness as evaluation indices for cell image resolution, the cell surface topography prediction model is established by quadratic orthogonal regressive rotational combination test. The scanning parameters on image quality of cell are detailedly analysised, the best conditions for cell imaging are obtained, and the experimental methods of living cancer imaging under physiological conditions are proposed, which provide reference scan parameters for microscopic imaging for cell research.Combinating atomic force microscopy with the temperature controller to conduct indentation experiments of living cells under physiological condition, the temperature controller is designed and built. The elastic properties and adhesion characteristics of living cancer cells are obtained, cancer cells and normal cells were compared. Cancer can be diagnosed by the elastic modulus and adhesion forces of cells, which provides a new way of cancer diagnosis.Conducting cell surface micro-machining and indentation experiment by AFM nano-machining system , the cell interior mechanical properties are obtained. Finite element simulation analysis of indentation experiment and micro-machining process on cancer cells is carried out, the results of the simulation and the measurement results of nano-indentation experiment were compared. The results show that, theoretical and experimental results have good agreement. The correctness of finite element analysis results are verified.The cell dynamic performance test system is established by AFM and SR830 lock-in amplifier. Cells were measured under different external noise frequency, the dynamic storage modulus, loss modulus, loss shear volume of the lung adenocarcinoma cells and lung squamous cell are obtained. The dynamic rheological properties of cells can be used to operate and control cells on a micro scale, which lays the foundation for the cancer treatment.The formula of the maximum contact pressure between the tip and the cells during the micro-cutting process is derived, and the layer-by-layer micro-cutting process of cells is carried out. As a result, the distribution status of elastic modulus of intracellular levels is obtained. The results show that the distribution status of elastic modulus of each processed layer of the cell is different, which is the interaction results of the cytoskeleton and the organelles inside cells.