Study On Preparation Technology Andsimulation Analysis Of Gradient Gelmicrospheres

Living cells in vivo live in a non-homogeneous biochemical micro-environment,and the key factors such as cell concentration and nutrient distribution have very important practical significance for cell survival,proliferation and differentiation and expression of biological functions.In the field of bio-manufacturing,it is one of the key research directions that how to quickly and effectively construct in vitro cell culture model to simulate the micro-environment in vivo to ensure the high survival rate of cells.So a three-dimensional cell culture method is proposed,and gel micro-sphere is a common three-dimensional cell culture micro-carrier,its structure is simple and symmetrical,using bio-compatible and biodegradable bio-gel material preparation and formation.It has great application value in the fields of chemical drug analysis and biological manufacturing,and is often used in drug screening,cell packaging,etc.This paper mainly focuses on the preparation technology and simulation analysis of gradient gel micro-spheres.The main research contents of this paper are as follows:1.Firstly,a preparation process of gel micro-spheres with different cell concentration gradients was proposed,and its process was briefly introduced,which mainly included three processes: mixing of cell suspension and sodium alginate solution,spraying dripping of cell-sodium alginate mixture,and curing and cross-linking reaction of gel micro-spheres.Mainly designs a dynamic mixing nozzle used in hybrid cells-sodium alginate solution and mixed droplet spray,in view of the dynamic mixing nozzle and mixing of the droplet spray drop process,respectively to build the corresponding theoretical equation and mathematical model,and the sodium alginate gel micro-spheres crosslinking curing reaction process are briefly analyzed.2.Based on the established theoretical mathematical model of mixing and droplet injection,the process of mixing and droplet injection of nozzle was simulated and analyzed by using COMSOL Multiphycis multi-physical field simulation software.Firstly,the influence of rotor diameter,number of blades,rotation speed and fluid viscosity on the mixing effect was analyzed.Then the influence of driving pressure,fluid viscosity and nozzle aperture on droplet jet forming is analyzed.3.Build an experimental platform for preparing gradient gel micro-spheres,and briefly introduce the modules of the platform.Firstly,the morphology of the gel micro-spheres with single and stable morphology was investigated and analyzed by the pore size of the needle nozzle,the driving pressure,the viscosity of sodium alginate solution and other factors.Then through the preparation of red and blue concentration gradient gel micro-spheres,it is proved that the nozzle has good mixing performance and droplet forming function.4.Conduct related cell experiments.The gel micro-spheres were prepared by using well-cultured chondrocytes,and the input of different concentration cells and sodium alginate solution was controlled to complete the preparation experiment of gel micro-spheres with different concentration gradients.Finally,through the three-dimensional culture of chondrocytes and cell death/activity staining counting,the influence of cell survival rate and cell concentration in different concentrations of cell gel micro-spheres was explored.