Experimental Study Of 3D Printed PLA/PBSA/BM Composite Scaffolds For Repairing Skull Defect

Background:Bone defects can affect the body’s physiological functions.In severe cases,it can lead to dysfunction,disability,and even disability.The treatment of bone defects mainly includes autogenous bone transplantation and biomaterial filling.However,the limited source of autogenous bone will cause new defects.Restriction of autologous bone transplantation remains a key challenge for clinical treatment.In the field of bone regenerative medicine,the preparation of bone scaffolds promotes the development of bone tissue engineering and plays an important role in bone tissue engineering.At present,3D printing and electrospinning technologies have been widely used in the preparation of biomimetic scaffolds to simulate natural bone tissue,guide bone cell growth,and promote bone damage repair.Therefore,it is still challenging to prepare a bone tissue scaffold with good mechanical properties and biocompatibility,and promote the growth of bone cells to repair bone defects.Objective:In this experiment,3D printing technology was used to mix polylactic acid(PLA),butylene glycol succinate(PBSA)and pig bone meal(BM)materials into 3D printed wire rods.3D printing was used to prepare substitute bones.In this study,the use of computers to help complete the design,rapid prototyping deposition technology manufacturing PL A/PBSA/BM composite scaffold,to conduct histocompatibility and osteogenic experimental research.Methods:1.Treat the pig humerus with proteinase,lipase,etc.,and then obtain the bone powder material by nano-grinding,then mix it with PL A and PBS A,and obtain the final bone material matrix through the screw extruder and other polymer material molding preparation process,detection The mechanical properties of composite scaffolds with different ratios determine the best modification scheme.2.Use Live/Dead kit to detect the survival rate of MC3T3-E1 cells on the surface of PLA/PBSA/BM composite scaffold,use Alamar Blue kit to detect the proliferation of MC3T3-E1 cells,and analyze MC3T3-using fluorescence staining and scanning electron microscopy Morphological structure of E1 cells3.Establish a 6mm critical bone defect model of New Zealand rabbit skull,which are blank group,autogenous bone group and composite material group.According to the established 4 weeks,8 weeks,12 weeks,and 36 weeks,the animals were sacrificed and specimens were collected at the same time for imaging examination and histological examination.Vitrea Core image analysis software was used to analyze and determine the repair of bone defects Area,calculate the ratio of osteogenesis volume to defect volume,and evaluate the osteogenesis of PLA/PBSA/BM composites.Results:1.When the PLA content is 80%,the PBSA content is 10%,and the bone meal content is 10%,the PLA/PBSA/BM composite material achieves the best mechanical properties.2.Under the observation of scanning electron microscope and fluorescence microscope,there are a large number of MC3T3-E1 cells,and the survival rate and proliferation rate of MC3T3-E1 cells are higher.3.Micro-CT scanning and reconstruction:In the blank group,a small amount of bone was seen at the edge at 4 weeks.Although the new bone tissue was generated at 8 weeks,12 weeks,and 36 weeks,the defect still did not heal,and there were voids.The autogenous bone graft group had healed at 4 weeks,and there was no significant change at 8 weeks,12 weeks,and 36 weeks.In the PL A/PBSA/BM composite material group,at 4 weeks,only a small amount of bone was formed at the edge.At 8 and 12 weeks,the new bone tissue was filled and the new bone trabecula was active,but the defect surface was too low.At 36 weeks,bone tissue became denser,and PLA/PBSA/BM composites were degraded in large quantities.4.HE staining results:at 4 weeks,a small amount of fibroblasts and fibrous connective tissue,at 8 and 12 weeks,a large number offibroblasts and fibrous connective tissue and bone tissue,at 36 weeks,bone tissue is more dense.Conclusion:The results show that the 3D printed PLA/PBSA/BM composite scaffold has good biological properties and biocompatibility,can effectively repair the skull of the New Zealand rabbit defect,provides a good microenvironment for the growth of bone cells,and promotes the development of bone cells.Grow.This composite scaffold has potential application prospects in the field of bone tissue engineering repair...