3D Printing And Performance Analysis Of Cartilage Tissue Scaffold

Cartilage tissue engineering as an important method to achieve cartilage tissue damage repair,the core of which is cartilage scaffold needs to meet the mechanical properties required for normal human activities,and the scaffold material itself needs to have good biocompatibility to facilitate inoculation of cell proliferation.In this thesis,cartilage scaffolds were prepared by using 3D printing cryogenic molding technology.The effects of material types,strands gaps,and strands staggered angles on the mechanical properties of scaffolds were studied.The selected scaffolds were subjected to biological experiments to verify that the materials meet the biological performance requirements of scaffolds.The scaffold is used in the bracket model structure.Based on this structure,various kinds of strands gaps and the staggered angles of the strands are selected,and multiple sets of bracket structure models are designed.The mechanical simulation of the designed model was found to meet the mechanical properties of the cartilage tissue scaffold.The cartilage tissue scaffolds were prepared by using a cryogenic molding technique using a biological 3D printer.In the material selection,PLA with good biocompatibility is selected and polyethylene glycol(PEG)is mixed at a certain mass ratio to prepare PLA,PLA: PEG(5:1),PLA: PEG(2:1)three kinds of materials,1,4-dioxane were selected as organic solvents,and the relevant printing parameters were determined through experiments.According to the requirements of the experiment contents,a total of twenty-seven groups of cartilage tissue scaffolds were printed by using three kind of materials.The physical properties of the printed cartilage tissue scaffold were analyzed.The prepared cartilage scaffold was measured and the scaffold was found to have a certain shrinkage rate.When the scaffold material was PLA:PEG(2:1).The scaffold shrinkage was low,and the scaffold material was easy to meet the purpose of scaffold design.The water absorption of the scaffold was tested.The test results showed that the water absorption of the scaffold increased with the increase of PEG content in the scaffold material.The material PLA:PEG(2:1)had the best water absorption in the three materials.The mechanical compression experiments were performed on the scaffolds.The results showed that the printed twenty-seven groups of scaffolds met the mechanical properties of the cartilage scaffolds.The experimental data was used to investigate the effects of three factors,scaffold materials,strands gaps,and strands staggered angles on the mechanical properties of the scaffolds.Biocompatibility analysis of cartilage tissue scaffolds.Rabbit chondrocytes were used as scaffolds to inoculate cells.The cells were inoculated on scaffolds.Afterculturing in vitro for a period of time,cell morphological observation experiments were performed.Fluorescence inverted microscope was used to observe the cell growth tendency on the scaffolds.It was observed that the scaffold material was PLA:PEG(2: 1)The cell growth was better than the other two materials.Using scanning electron microscope,it was observed that when the scaffold material was PLA and PLA:PEG(2:1),the cells successfully adhered to the cartilage scaffold for proliferation,and the material was PLA:PEG(2:1)when the cell growth rate was faster.To verify the activity of MTT activity on the scaffold,the experimental results showed that the three materials had no negative effect on the growth of chondrocytes.From the results of the chondrocytic cell secretion glycosaminoglycan(GAG)assay,the scaffold has no negative effect on cells and can maintain chondrocyte activity to promote cell proliferation.When the scaffold material is PLA:PEG(2:1),it is compared with traditional Materials has a higher effect on cell proliferation.The above experiments proved that PLA:PEG(2:1)has good biocompatibility.