Experimental Study On The Reconstruction Of Mandibular Defects By 3D Bionic Printing Tissue Engineering Bone With RhBMP-2 Sustain-release System Composite

OBJECTIVE:The 3D bionic printing manufacturing polylactic-co-glycolic acid/ nanohydroxyapatite(PLGA/nHA)scaffold-bone morphogenetic protein-2(rhBMP-2)tissue engineering bone composite was detected biological activity,mechanical properties,and the biological activity of its controlled release rhBMP-2.On this basis,To investigate its ability of 3D bionic printing manufacturing PLGA/nHA scaffold/rhBMP-2 sustained release tissue-engineering bone on repairing rabbit cranial defects.METHODS:Use 3D bionic printing technology to construct rhBMP-2 sustained-release system tissue engineering bone scaffold.Animal models of bilateral critical mandibular bone defects were established in 27 New Zealand white rabbits.One side was implanted a 3D bionic printing manufacturing PLGA/nHA scaffold/rhBMP-2 sustained release tissue-engineering bone(experimental side);and the other side was implanted a 3D-printing manufacturing PLGA/nHA scaffold(control side).Manbidular specimens were harvested at postoperative days 30,60 and 90 to carry out visual observation,CBCT,Micro CT,histological and immunohistochemical examinations.The SPSS22.0 statistical software for statistical analysis.RESULTS:Visually observed and three-dimensional reconstruction of the experimental side at different time points showed that the formation of bone speed and the formation of bone are better than the control group.The outcomes from micro-CT analysis revealed that the amount of newly formed bone volume,bone trabecula in experimental side and it in control group had significant differences(P<0.05).Histological and immunohistochemical examination showed that the osteogenic ability of the experimental side was superior to the control side in the repair of bone defects.CONCLUSIONS:3D biomimetic printed PLGA/nHA-rhBMP-2 chitosan nanospheres sustained release system tissue engineered bone scaffolds.After implantation in the host,rhBMP-2 can mimic the in vivo release process to induce osteogenesis.The implanted tissue-engineered bone scaffold can successfully induce new bone formation and reconstruction in the bone defect area.The 3D bionic printing manufacturing PLGA/nHA scaffold/rhBMP-2 sustained release tissue-engineering bone can satisfy the repair and reconstruction of rabbit experimental mandible defect and meet the need of repair and reconstruction of experimental rabbit mandibular defect.