The Fabrication Technology And Performance Analysis Of Bone Scaffolds Manufactured By 3D Printing And Filament Winding

Bone defect repair is the hot and difficult topic in the field of clinical research. At present, the porous scaffold applied as the artificial extracellular matrix plays an essential role in the tissue engineering, which is one of the most important methods in bone defect repair. The medical application of the porous scaffold is restricted due to its bad biocompatibility, low preparation efficiency and poor mechanical properties. This research focus on the forming method of 3D printing and filament winding for the porous scaffold and explore the internal relation among the material, porosity, structure and mechanical properties to lay the foundation for the formation and application of the porous scaffold.According to the requirement that the pores of the porous scaffold need to be highly interconnected, a modeling method for the porous scaffold of interconnected pore is proposed in this research. After analyzing the mechanical properties and manufacturability of different patterns of pore interconnection, the porous scaffold model which the pores are interconnected in three directions is constructed by SolidWorks. To improve the compressive property of the model, the axial, radial and circumferential diameters of the pores are optimized by utilizing the RSM method in ANSYS. Then porous scaffold model with optimal mechanical properties for the porosities of three kinds, which also meets the requirement of cell culture, is obtained.Comparing the advantages of different biomedical materials, NPHA, PLA and PCL are chosen as the suitable materials and the proportion of these three materials is determined by experiments and consulting other researches. For the forming method of 3D printing and filament winding, the orthogonal experiments are respectively designed and the test pieces are prepared. After analyzing the main factors that affect the forming efficiency, a group of factors are recommended. A comprehensive comparison between these two forming methods are carried out taking account of the forming efficiency, cost and structure feasibility.The experiment is undertaken to test surface morphology, pore size, composition of materials, porosity, density and mechanical properties of the porous scaffold. The pore connectivity of the scaffold formed by 3D printing is found better than the one formed by filament winding through the scanning electron microscope test during which the surface morphology and average pore sizes are characterized. The biocompatibility is verified through the phase analysis of X-ray diffraction experiment by characterizing the composition of the proposed materials. The porosity and density of the scaffold is measured by the desilting method and it is found that the density of the scaffold formed by 3D printing is double the one formed by filament winding. The mechanical properties are also measured by the uniaxial tensile and compression test and the compressive property of the scaffold formed by 3D printing is superior. The experiments verify the feasibility of the proposed forming method for the scaffold.