Construction And Application Of Microfluidic Chips For Three-dimensional Culture Of Tumor Cells

With the rapid development of tissue engineering,three-dimensional cell culture technology which can simulate the human microenvironment came into being,gradually showing a more comprehensive advantage than conventional two-dimensional cell culture methods.The application of three-dimensional cell culture technology in tumor research can explore such areas as tumor invasion mechanism,tumor microenvironment,and tumor drug screening,which can effectively solving the problem of low accuracy of two-dimensional culture experimental results.Microfluidic chip technology is widely used in cell research due to its many advantages such as micro-scale and high efficiency.The on-line long-term culture for one or more kinds of cells can be realized through reasonable designed cell culture architectures,which provides a well implementation platform for cell-level research of life science field.In this paper,microfluidic technology and three-dimensional cell culture technology are combined to design and fabricate two microfluidic chips with different structural parameters,which can realize three-dimensional culture of tumor cells on the chips and subsequent functional applications.Taking into account factors such as cell culture requirements and chip development process optimization,a chip structure with single-layer flow channel and round culture chambers was designed,which can effectively reduce the direct shear stress on cells.In the chip design theory,the functional evaluation indicators of three-dimensional culture chip such as cell aggregate parameters,initial cell homogeneity,and high throughput were proposed to evaluate the culture performence of chips.The two kinds of chip were numerical simulated through computational fluid dynamics(CFD)method to compare the flow field characteristics of chips with two different structural parameters.The changing process of speed and displacement of cells flowing into a single culture chamber were investigated,and the shear force of tumor microspheres suffered from drug delivery was observed,which provide a powerful reference for the actual chip usage.In the experimental study,a microfluidic chip cell experimental platform was set up.HeLa cells were selected as the tumor cell representative for three-dimensional culture experiments and tumor microspheres drug delivery experiments.The injection time(1h)and the initial cell concentration(1×107 个/ml)were controlled in experiments,the influence of structural parameters and injection velocity on the threedimensional culture performence was studied from the perspective of different chip functional evaluation indicators.On the basis of the three-dimensional cell culture experiment,the function development of the chips was performed,which is anticancer drug screening on the formed tumor microspheres.The intrinsic relationship between the diameter of the tumor microspheres and the drug effect was obtained with different drug concentration conditions,and the utility of the chip administration function was verified.Through the discussion and analysis of the research results,the more suitable structural parameters and injection speed(0.15μl/min,3μl/min)for three-dimensional cell culture were obtained.This study provides important reference value for low-cost drug development and high-throughput tumor mechanism research,and provides a clear guiding role for optimal design of three-dimensional culture chip structures in the future.