Study Of The Mechanical Properties Of Porous 3D Lattice Structures For Tissue Engineering Scaffolds

Skin tissue engineering covers biology,materials science,and medicine,involving seed cells,scaffold materials,and growth factors,with the aim of preparing organismal substitutes that can be used for defect site treatment.This method overcomes the two biggest drawbacks of graft rejection and limited skin sources compared with allogeneic and autologous skin grafts,and shows a broad prospect in the treatment of skin damage.The scaffold structure has an important role in the development of tissue-engineered skin,which can meet the requirement of high porosity and also have certain mechanical properties to avoid the easy destruction of the scaffold structure and provide a good buffer protection for the seed cells placed in it and provide a good growth space for them.Therefore,this paper investigates the design preparation and mechanical properties of 3D porous dot matrix structure based on truss single cell and DLP forming technology for the porosity and mechanical property requirements of the scaffold structure as follows:To investigate the influence law of DLP process parameters on the forming effect of 3D porous dot matrix structure.The influence of the array direction of truss single cell on the structural connection strength is investigated,and three new types of 3D porous supports are designed accordingly;using the DLP process,the influence of process parameters such as layered thickness,exposure time per layer and forming speed on the actual forming effect of3 D porous dot matrix structure is investigated,and the 3D porous dot matrix structure with intact structure and clear pores is prepared.The tensile mechanical properties of different configurations of dot matrix structures were studied,and the configurations of dot matrix structures were selected based on tensile toughness.Tensile simulations and uniaxial tensile experiments were used to find out the stress concentration region of the structure after being strained,and the stress-strain trend of the structure during the tensile process was investigated,and the differences in the tensile mechanical properties of the structures were analyzed and compared.For the best structure,the influence of the change of support rod diameter on the mechanical properties of the three-dimensional porous dot matrix structure is investigated.Tensile simulations and uniaxial tensile experiments were used to find out the influence of the change of the support rod diameter on the tensile properties of the three-dimensional porous dot matrix structure,and it was analyzed that the effective elongation and the peak stress of the structure would increase with the increase of the support rod diameter within the limit size of the process;uniaxial compression tests were repeated,and the results showed that the preferred structure not only had a wide stress plateau when it was compressed,but also the percentage of the stress plateau segment increased with the increase of the support rod diameter.The results show that the preferred structure not only has a wide stress plateau when compressed,but also the percentage of stress plateau section increases with the increase of support rod diameter.The three-dimensional porous dot matrix structure studied in this project has both good tensile fracture rate and tensile strength,and a wide compressive stress plateau.Therefore,it can not only keep the structure intact under large tensile rates,but also protect the integrity of the seed cells in the porous dot matrix structure when it is compressed,providing scientific guidance for the design and application of skin tissue engineering scaffolds,and at the same time,the better mechanical properties of the structure can also be used in the fields of fragile product clamping and flexible electronics.