Real-Time And Quantitative Study Of Mechanical Properties Of Human Umbilical Vein Endothelial Cells During Cell Ddhesion

Cell-matrix adhesion is a dynamic and complex process.However,there is a lack of techniques which can simultaneously capture dynamic information of multiple cellular mechanical properties.When cells are cultured in vitro or grown in vivo,they are not only coupled with extracellular matrix,but also connected with adjacent cells.Therefore,it is crucial to study the relationship between cell-cell interaction and cell-substrate interaction.It is theoretically predicted that cell traction force decreases exponentially with the increase of the thickness of the hard substrate,however,there are no experimental results have been published because of the absence of suitable method for measuring traction forces of cells adhered to hard substrates like cell culture dishes.In this thesis,human umbilical vein endothelial cells were used as the study object,and a new method based on double resonator quartz crystal microbalance technology was established to simultaneously monitor cell traction force and viscoelasticity and applied for the study of the force dynamics of cells during their adhesion.The established method was also applied for the study of the effects of substrate thickness and cell density,and for drug evaluations.The main results are as follows:(1)the cell traction force and viscoelasticity was the largest when the concentration of fibronectin was 20 ?g/m L modified on the surface;(2)the traction force was the largest and the viscoelasticity was the weakest when the thickness of hard matrix was 10 nm,while the traction force was the smallest and the viscoelasticity was the strongest when the thickness was 200 nm;(3)the traction force and viscoelasticity was the largest when the cell number was 40,000;(4)rapid evaluation of drug efficacy can be achieved by capturing changes in cell traction and viscoelasticity.In conclusion,the method for the study of cell mechanics proposed in this work can achieve simultaneous and quantitative study of cells generated force and viscoelasticity in the process of cell-substrate adhesion,which provides a new method for studying the dynamic relationship between cell-cell interaction and cell-matrix interaction,and opens new avenue for drug efficacy evaluation,as well as offers new opportunity for improving cellular force sensing,and is expected to be widely used in cell mechanics and cell biology.