Development Of Microfluidic Chip With Controllable Liquid Environment

As the basic unit of life,the behavior of cells determine many life processes.In the meantime the ever-changing physical signals(including mechanical and morphological signals,etc.)and chemical signals(such as cytokines)in the biological microenvironment jointly determine the processes of cell proliferation and apoptosis.Although many technology has gradually applied to the study of dynamic signals,such as high-resolution cell traction force microscope technology,system dynamics methods,dynamic mechanical deformation and other methods,to accurately simulate the complex physical and chemical environmental conditions in vivo is still difficult.This paper proposes to construct microfluidic chip to study the influence of dynamic physical and chemical signals on cell behavior and the mechanism of action.The chip can cultivate cells and precisely control the micro-environmental conditions of the cells through valve-controlled microfluidic technologyIn this study,two microfluidic chips regulate the dynamic physical and chemical signals of cells respectively.The hybrid chip that mixes supernatants of different types of cells to generate dynamic chemical signals and the oscillating fluid chip that applies dynamic physical signals to single cells by shear flow.(1)The hybrid chip can introduce dynamic biochemical signals by mixing of supernatants on 2 to 8 types of independently cultured cells(ie,without physical contact).Specifically,cell is culturing in independently culture chamber,the multiple microfluidic valves precise control the liquid flow direction and speed.Cytokines secreted by cells(dynamic chemical signal)is introduced into the culture environment of the target cell.(2)The oscillation chip generates a reciprocating oscillating flow field in the culture chamber by controlling the timing and fixed-point switching of the microfluidic valve,thereby generating dynamic mechanical signals with controllable frequency and amplitude on the cells.The oscillating frequency of the reciprocating flow field is controlled by the micro flow valve,the amplitude of the flow field fluctuation is controlled by the number of micro flow valves.(3)3T3 fibroblast cell line and Hep G2 hepatoma cell line was used in study the effect of dynamic physical and chemical signals on cells.The study found that: a.Fibroblast cells can promote tumor cell growth through secreted cytokines and chemicals(ie,dynamic chemical signals)without physical contact;b.Cell mortality and the frequency of mechanical signals are directly related.In summary,this research developed and designed a fluid control device that can generate dynamic physical and chemical signals in the cell microenvironment based on valvecontrolled microfluidic technology.Due to the microfluidic chip has the advantages of high integration,no external controller,and low cost,this paper may lay the experimental foundation for the future exploration of the regulation and control effects of dynamic physical and chemical signals on life processes.