Experimental Research Of Repairing Osteochondral Defects Of Pig Knees By Using The "Interlayer Structure" Scaffold Composite With Autologous BMSCs

Objective:To estimate the effectivity of repairing osteochondral defects of mini pig knees by using the “Interlayer structure” nano-hydroxyapatite/CPPf/PLLA biominetic integration scaffold composite with autologous BMSCs.Methods:Nine mini pigs were involved in the experiment.The experimental and negative control groups osteochondral defects were made in ipsilateral femoral trochlear articular surface of same animal,six mini pigs in total.Then these animals were randomly divided into two groups.The experimental group,the “interlayer structure ” nano-hydroxyapatite/CPPf/PLLA scaffold composite with autologous bone marrow mesenchymal stem cells(six pigs,twelve knees).Negative control group,CPPf/PLLA scaffold without “interlayer structure ”(six pigs,twelve knees).And yet blank control group,without any implant(three pigs,three knees).At 12,24 weeks after surgery,Gross observation,histological evaluation,MRI scanning and Pineda scoring were examined.Results:Gross observation and MRI scanning results showed that in the experimental group had a more obvious repaired trend than the other two groups,but the osteochondral defects were not fully repaired.Histological evaluation indicated that repaired tissue of three groups were mainly fibrous tissue in the cartilage area that had little or no cartilage cells.The subchondral bone area were also not show the osteoblast appeared.On 12 and 24 weeks,Pineda score show three groups had no difference exited(P>0.05).Conclusion:The “interlayer structure ”nano-hydroxyapatite/CPPf/PLLA scaffold composite with autologous bone marrow mesenchymal stem cells can not repair pig knee joint osteochondral defects effectively,repaired tissue were mainly fibrous tissue.