Research On Preparation Of3D Porous Scaffold Of Tissue Engineering Based On Supercritical Fluid Technology

The core of tissue engineering is the fabrication of a complex three-dimensionalspace with cells and biomaterials. The main content of current research focused onbiodegradable scaffolds, aspects of seed cells and in vitro culture conditions. Theconstruction of the ideal three-dimensional scaffold is a prerequisite for successfulresearch of tissue-engineering artificial organs. Supercritical CO2induced phaseseparation-cycle drying process provided a new way for the porous scaffold in tissueengineering with its unique advantages. The porous scaffolds structure with thistechnology prepared was controllable, high porosity, good interoperability and almost nosolvent residue. In the development of porous scaffolds in vitro, no matter the seed cellsran into the scaffold, or its excretion of waste discharged scaffolds, they both need thenutrient solution to be brought into or taken out. Therefore, the flow of the nutrientsolution, cells and metabolic waste for the profitable living in vitro culture plays asignificant role.In this paper, with poly methyl methacrylate, poly lactic acid and the mixture ofpolytechnic acid and polycaprolactone as model materials, acetone and dichloromethaneas solvent, it made an experimental study on the feasibility of the preparation of tissueengineering scaffolds by Supercritical CO2induced phase separation-circulation dryingprocess. The whole internal structure of the support is characterized through the SEM; Theimpact of operating parameters on the pore structure is also examined, such as polymerspecies, polymer concentration, pressure in the autoclave, operating temperature, dryingcycle time and CO2flow. The results showed that different operating parameters andpolymers make separate porous scaffold structure forms. With the increasing of polymerconcentration and operation temperature, the size of pore scaffolds decreases. With theincreasing of the pressure in the autoclave, the aperture of scaffolds increases gradually.With the increasing of CO2flow rate and different polymers, change rule of the size of thepore structure is different. Circulation drying time made a little impact on the scaffoldsaperture, but it made a significant influence on its feasibility.Combined with the bionics and related research on the internal structure of thescaffolds at home and abroad, the paper constructed bone scaffold models of differentgeometric parameters, analog cells, and nutrient solution flow conditions in the scaffoldsusing the FLUENT software. It is concluded that the different structural bone scaffolds velocity and pressure distribution of the internal flow field. By making a contrastiveanalysis with the simulated result, the internal organizational design parameters of scaffoldfor tissue engineering is optimized and a certain amount of datas and a theoretical basis forthe internal bone scaffold structure design is provided.