Research On The Application Of Nacre Powder Combine With Platelet-rich Fibrin In The Cranial Defect Repairing Of Rabbit

Objective: Nacre powder(NP)belongs to the organic-inorganic natural biomaterial,which has the ability of bone induction and good biocompatibility.Platelet-rich fibrin(PRF)applied to healing soft and hard tissue and osteogenesis in area of maxillofacial surgey as an autograft and rich in multiple of growth factors and platelets.Evaluated osteogenic efficacy of mixture materials which contains nacre powder and PRF in rabbit cranial defect model.Methods: We extracted enough blood from Wistar rats and New Zealand rabbits obtain PRF after centrifuge,and the morphological characteristics were observed by scanning electron microscope(SEM).Three groups of WSM,PRFe and mixed materials cultured with osteoblast progenitor cells(MC3T3-E1)in vitro experiment.Cell proliferation and adhesion were detected by CCK-8 and bone differentiation was detected by alkaline phosphatase(ALP)activity.12 New Zealand rabbits being the application in our study,and four cranial defects mode had 8mm of diameter treated as the experimental group: nacre powder combine with platelet-rich fibrin(NP/PRF),PRF as control group 1,NP as control group 2 and performed the blank control group.The animals were killed at 4,8 and 12 weeks,respectively.The osteogenic effect was analyzed by gross specimen observation,Micro CT detection,histological analysis and immunohistochemical detection.The statistical software SPSS 19.0 was used in data.Result: We didn’t extract PRF from the Wistar rats’ blood,but plenty of PRF output from New Zealand rabbits.The SEM results indicated that the PRF clot display a three-dimensional reticular structure and gathering platelets and leukocytes.The increased cells proliferated and ALP activity expression of the mixed materials was obvious in CCK-8 result.In NP/PRF group,better osteogenesis was shown at 4,8 and 12 weeks after operation,and histopathological suggested that activeformation of new bone,good bone mineralization and mature trabeculae;Micro CT observed the notable new bone formation area,the increasing bone mineral density,and highly proportion of new bone to total volume.Immunohistochemistry indicated that the expression of BMP-2 and VEGF increased and osteogenic effect enhanced,and there have significant difference between NP/PRF group and other(P<0.05).Conclusion:Firstly,we screened the common used animals and verified New Zealand rabbits as sake of object.PRF clot possess a three-dimensional reticular structure and full of platelets and white blood cells,which is beneficial for the maxillofacial tissue repairing.Mixed materials can promote the proliferation of osteoblast progenitor cells and differentiation shortly,which means that materials get better osteogenic properties.Moreover,NP/PRF is regarded as one of the newly effective treatment for bone defect with powerful osteo-inductivity.In summary,NP/PRF mixed material not only exhibit good biocompatibility and osteogenic property,but also bone tissueinductivity,further gives an insight into jaw defect.