Experimental Study On Construction Of GO-BFP-SPEEK Composite And Repair Of Femoral Condyle Defect In Rabbits

Objective: A variety of sulfonated polyether ether ketone composites were prepared and implanted into the rabbit femoral condyle defect model to investigate the bone integration performance of the composite materials,which provided references for relevant scientific experiments and provided theoretical and experimental basis for the clinical application of sulfonated polyether ether ketone bioactive composites.Methods:SPEEK was prepared by sulfonating PEEK with concentrated sulfuric acid.Graphene Oxide(GO),Bone Forming Peptide(BFP)and Sulfonated Polyetheretherketone(SPEEK)were blended together.Graphene oxide/sulfonated olyetheretherketone(GO-SPEEK),bone forming peptide/sulfonated polyetheretherketone(BFP-SPEEK),graphene oxide/bone forming peptide/sulfonated polyetheretherketone(GO-BFP-SPEEK)composites were prepared,and their in vitro physical and chemical properties and cytology were studied(the material preparation and in vitro study were completed by the school of chemical engineering,sichuan university).Twenty-four healthy adult New Zealand white rabbits were randomly divided into four groups(n=6).The animal models of bone defect with 6mm diameter and 10 mm depth were made by bilateral lateral femoral condyles.The prepared SPEEK,GO-SPEEK,BFP-SPEEK,GO-BFP-SPEEK composites were implanted into bone defect sites.The rabbits were divided into group A(SPEEK),group B(GO-SPEEK),group C(BFP-SPEEK)and group D(GO-BFP-SPEEK).At the 4th and 8th weeks after operation,the specimens were taken for gross observation,X-ray examination,micro-CT scanning analysis(bone volume fraction,trabecular thickness,trabecular number,trabecular space),push-out test,hard histology and scanning electron microscopy to observe the formation of new bone.SPSS23.0 statistical analysis software was used to analyze the experimental data.Results: Visual observation of the osteogenic area and X-ray examination showed that the placement of the implanted materials was good.The bone mass and speed of B,C and D were better than those of group A at 4 weeks after operation.The bone mass and speed of D were better than other groups at 8 weeks after operation.Micro-CT scan showed that the new bone trabeculae with small number,small shape and sparse arrangement were formed on the surface of each group at 4 weeks after operation.At 8 weeks after operation,the surface of each group was tightly wrapped with reticular new bone.The number of trabeculae in group A was small,sparse and few;the number of trabeculae in group B and C was large and orderly;the structure of trabeculae in group D was orderly,interlaced and braided,which was similar to normal bone tissue.The bone volume fraction(BV/TV),trabecular bone(Tb.N),trabecular space(Tb.Sp)and trabecular thickness(Tb.Th)of the same group of materials were better than those of the same group at 8 weeks after operation,and there was significant difference in t-test analysis(P < 0.05).The BV/TV,Tb.N,Tb.Sp and Tb.Th indices in group D were significantly better than those in group A,B and C at the same time point after implantation,and there was significant difference in one-way ANOVA(P < 0.05).The experimental results showed that at the same time point,compared with other groups,the maximum push force of group D was larger,and the difference was statistically significant(P<0.05).At different time points,compared with the same group,the maximum push force gradually increased,and the difference was statistically significant(P<0.05).The histological observation of non-decalcified bone showed that the implant material-bone interface in group A was thick and loose soft tissue 4 weeks after operation,the implant material-bone interface in group B,C and D was fibrous membrane of connective tissue,and new bone was occasionally found on the surface of implant material in group A,B,C and D.At 8 weeks after operation,a small amount of new bone tissue was observed on the surface of implant material in group A,and new bone grew into the material interior in group B and C.Bone tissue and new bone grow inside the material.In group D,there are a large number of new bone tissue on the surface of the implanted material,even encircled in a circular shape,and new bone grows inside the material.Scanning electron microscopy showed that the surface of the implant had unequal pores.At 4 weeks after surgery,a small amount of new bone ingrowth was found in the pores of the B,C,and D implants.No new bone ingrowth was observed in the pores of the surface of group A implants.At 8 weeks after operation,the growth of new bone was significantly increased in the pores of the B and C implants,and a large amount of new bone ingrowth was observed in the pores of the D group.Only a small amount of new bone ingrowth was seen in the pores of the surface of group A implants.Conclusion:The four groups of GO-BFP-SPEEK,SPEEK,GO-SPEEK and BFP-SPEEK have good biocompatibility in vivo.The GO-BFP-SPEEK composite is superior to SPEEK,GO-SPEEK and BFP-SPEEK in its ability to repair and promote osteogenesis of the defect of rabbit femoral condyle,significantly improving its ability of bone integration in vivo and effectively repairing the defect of rabbit femoral condyle.