Development Of Cell And Scaffold Oriented Fluid Shear System

Under physiological condition,all kinds of cells surrounded by a fluid environment are subjected to the shear of fluid,and the shear force affects cell morphology and behavior in many ways.Under the condition of cell culture in vitro,it is of profound significance to simulate the effect of mechanical environment on cells in vivo and to induce the biological behavior of cells in vivo.In this paper,a set of fluid shear system with standard size and suitable for cell culture and scaffold in laboratory is developed,which is convenient for the research of cell mechanics.The system is composed of three subsystems:drive control system,circulation culture system and perfusion test system.The circulation culture system is the core of the whole system,which is comprised of a new type of flow culture chamber.The inoculation room can use the universal consumable Petri dish or six hole culture plates of the biological laboratory;the perfusion cover is made of the additional molding silica gel material,which is prepared by pouring molding technology of the 3D printing mold.The exceptional characteristics of the material make the device have good sealing performance,without additional sealing rings,and the silica gel cover of the required cavity can be quickly prepared according to the experimental requirements.Three kinds of parallel height,0.3mm,0.5mm and 0.8mm,were designed for the flow culture chamber.The model of the flow culture chamber was designed by gambit software,and was imported into fluent for hydrodynamic analysis.The velocity range was set from 0.01m/s to 0.23m/s,and each time the velocity increased by 0.01m/s,the shear force and uniform flow field range of the bottom surface of the flow culture chamber with different heights were obtained,and compared The effects of the three factors on the bottom shear force of flow culture chamber were studied.The results show that the flow field of the flow culture chamber at the height of 0.3mm,0.5mm and 0.8mm is not uniform except in the adjacent area of the inlet and outlet,and the uniform fluid shear force can be produced in the center area of the bottom surface;the theoretical shear force values of 68dyn/cm~2,23dyn/cm~2 and 11dyn/cm~2 can be achieved in the cavity at the height of 0.3mm,0.5mm and 0.8mm;The higher the height is,the smaller the shear force change rate is with the increase of velocity.On the basis of parallel flow culture chamber,we further studied and designed two kinds of irregular flow culture chamber,one is a slope type flow culture chamber with a height of 0.3mm in the middle and 0.6mm on both sides;the other is a corrugated flow culture chamber with a height of 0.3mm at the inlet and 0.6mm at the outlet.And the hydrodynamic simulation is performed.The results show that:in addition to the sudden flow field in the adjacent area of the inlet and outlet,the uneven but continuous shear force can be generated at the same time on the bottom of the flow chamber,and the shear force of the slope flow chamber gradually increases in the direction of the flow field;the shear force in the middle of the corrugated flow chamber is the largest,as the ripple decreases one by one,and the flow chamber with this special structure can At the same time,the mechanical behavior of the bottom culture cells under various shear forces was studied.The system was used only for cell culture in vitro.The cells were stimulated to grow for 2 hours under the shear force of 8dyn/cm~2,10dyn/cm~2 and 12dyn/cm~2,and the response of cells in vitro to fluid shear was explored.The results showed that the number and shape of cells changed little under the effect of 8dyn/cm~2 shear force.When the shear force reached 10dyn/cm~2 and 12dyn/cm~2,it was observed that the adhesion of cells began to decline,and with the increase of shear force,the cells began to show obvious orientation.The fluid shear system designed in this study can not only shear cells in vitro,but also shear scaffolds.We established a simple scaffold model by finite element method and investigated the effect of fluid shear force on scaffold and seed cells.