Muti Microenvironments Parameter Control Microfluidic Device For Cell Research

The cellular microenvironment is an increasingly discussed topic in cell biology as it plays important roles in many complex biological processes, such as immune, wound healing, angiogenesis and tumor metastasis.The in vivo microenvironment is an integration of a complex array of global as well as local stimuli and interactions that can be charaterized as a combination of two factors: biochemical factors and biophysical factors. Current cell culture in vitro models are limited in the scope of biochemical or biophysical factors that can be controlled, and often cannot be imaged at high resolution during the course of an experiment. The rich information available in microenvironments is often overlooked. For this reason, much emphasis has been placed over the past few decades in closely mimicing in vivo conditions. Progress in microfabrication technologies has paved the way for new approaches for manipulate and monitor cells in an environment that closely mimics in vivo conditions. The ability of microfluidic chip to precisely control the microflows makes it possible to mimic the microenvironment of cells in physiological or pathological states, which provides many distinct advantages to cell research.In this study, our objective is to set up a microfluidic device for 3D cell culture in hydrogel with the capability to closely mimic in vivo microenvironments. Full-text includes the following specific research:①Microfluidic chip design and fabrication:A microfluidic chip, with a middle channel for 3D cell culture and two side channels for delivering cell culture medium, was designed and fabricated using standard soft lithography and replica molding techniques. The structure of the microfluidic chip and fabricating techniques was discussed.②Demonstreation of chemical concentration gradient: Gradients were set up by Solute diffusion and characterized using fluorescence microscopy. With a flow rate of 2uL?min-1 in each side channel, the concentration gradients remained constant after 6h.③Demonstreation of pressure gradient: Reservoirs were connected to microfluidic channels por imposing pressure gradient. Interstitial flow across the gel scaffold was generated by a 100Pa pressure difference between two side channels.④3D cell culture and Cytoskeleton Staining: Human adult dermal microvascular endothelial cells (HMVEC) were maintained in 3D culture with collagen type I and observed with confocal microscopy. Cytoskeleton of cells under 3D culture and 2D culture were compared.This microfluidic device is simple and easy to operate, which enables to mimic the complicated microenviroments in vivo. The device allows multi parameter control of microenvironments。With this platform we are able to control: (1) soluble factor and its concentration gradient, (2) pressure gradient and interstitial flow through the matrix, (3) properties of cell culture scanffold. The microfluidic chip is able to accommodate different physiologically relevant features and monitor cells in real-time, facilitating the better understanding of interaction between cells and microenvironments.