Research On The Fabrication Of HA Scaffold Based On Mask Projetion Stereolithography

Additive manufacture is a new technology,which based on the digital model,stacking the material layer by layer into physical object.It is an important part of advanced manufacturing technology,specialized in personalized customization.Mask projection stereolithography belongs to the additive manufacture,developed on the basis of stereolithography appearance(SLA),has advantage in efficiency and precision process.Bone defects and repair are the active problems in the field of orthopedics,and the scaffolds for the bone tissue require personalized customization.It is necessary to apply the mask projection stereolithography technique to the preparation of bone tissue scaffold.Hydroxyapatite(HA),as the main component of human bone mineral,is widely used in scaffolds for repairing bone defects.Therefore,it has practical significance to fabricate HA scaffolds by the mask projection stereolithography techniqueStudy on the formation and solidification process of bone tissue engineering scaffolds by forming HA scaffold with mask projection stereolithography technology.In this paper we used HA powder and photosensitive resin as raw material for molding.After viscosity test the preparation of HA mass ratio of 30wt% to 40wt% mixture was achieved for the curing performance test to obtain the exposure parameters and complete the fabrication of HA scaffold.The sintering process of the scaffold was analyzed by studying the mechanism of it.According to the thermal analysis data,it was observed that the binder was decomposed at 500 ℃,and the temperature rating as 1 ℃/min could ensure the decomposition process did not affect the scaffold structure.The influence of the ratio of slurry composition,sintering temperature and holding time on the properties of the scaffolds was analyzed by orthogonal test.The slurry with 40wt% of HA was determined and maintained at 1200℃ for 2h can obtain better performance index.The process parameters of the sintering process were optimized,and analysis was carried on phase and microstructure of scaffolds.The performance of the optimum scaffolds prepared was tested,which processed excellent mechanic property and has a certain strength orientation.The compressive strength could reach 4.8MPa in horizontal direction,and it could reach 11.69 MPa in vertical direction,which was significantly better.The biological properties of the scaffolds was evaluated by the vitro experiment to evaluate biocompatibilities.The good attachment of MC3T3-E1 cells on scaffolds was observed in SEM images.The absorbance test also proved good proliferation state of cells.By combining mask projection stereolithography technology with sintering process,this thesis realized the fabrication of HA scaffolds,which showed the promising clinical application after mechanical and biology test.