Experimental Study On The Preparation Of β-tricalciμm Phosphate With Different Pore Sizes And The Promotion Of Bone Defect Repair

Objective: The aim of this study was to prepare porous tricalciμm phosphate scaffolds with different pore sizes and to explore the optimal pore sizes of porous tricalciμm phosphate scaffolds for repairing bone defects.Method : Methods for the preparation of 3D porous three-calciμm phosphate scaffolds: the mass ratio of 10% HPMC three-calciμm phosphate powder was mixed and ammonium polyacrylate was used as dispersant,then the β-TCP slurry is obtained.And 3D printing rapid prototyping technology was used to prepare porous three-calciμm phosphate scaffolds with different pore sizes.By calcining,the products were sintered into shapes,and the scaffolds with different pore sizes were obtained.Three kinds of β-TCP scaffolds with different pore sizes(200±20μm,400±20μm and 600±20μm)were implanted into the rabbit model of large radius defect.The right radius was observed by the general observation,X-ray examination,bone alkaline phosphatase(BALP)testing,and histological observation at 4,12,and 24 weeks after the operation.Result:With the increase of the pore size of β-TCP scaffold material,the porosity of scaffold material increases,and the compressive strength of scaffold material decreases.Three kinds of β-TCP scaffolds with different diameters were implanted into the rabbit bone defect model.the X-ray examination at 4,12 and 24 weeks showed that the bone defect healing was better in the 400±20μm scaffold material group with three pore sizes.The BALP values in 400±20 μm group were higher than those in the other groups at 4 week(P < 0.05),and it has statistical significance,but there were no statistical significance among the three groups at 12 and 24weeks(P > 0.05).Histomorphology analysis indicated that the area of new bone formation in 400±20 μm group was larger than those in the others(P <0.05).Histomorphology analysis indicated that the area of new bone formation in400±20 μm group was larger than those in the others group,the analysis of imaging showed that the percentage of new bone area was the highest in the 400±20μmmaterial group(P < 0.05).Conclusion: With the increase of the pore size of β-TCP scaffold material,the porosity of the scaffold material increases,and the compressive strength of the scaffold material decreases.Porous β-TCP scaffold material has good biocompatibility and can support bone growth.The pore size of β-TCP scaffold material can affect the osteogenic capacity of bone biomaterials.In this study,the440±20 μm scaffold material has better osteogenic capacity for repairing bone defects.