Repair of rabbit segmental radial defect by using bone mesenchymal stem cells into the wrapped-core structure composite scaffold

Objective To repair segmental radial defect by using bone mesenchymal stem cells (BMSCs) cultured in vitro for 3 weeks under osteogenic medium into a porous wrapped-core structure composite scaffold composed of poly(lactic-co-glycolic acid)/β-tricalciumphosphate (PLGA/β-TCP) skeleton wrapped with type Ⅰ collagen.Methods 1.5 cm segmental radial defects were created bilaterally in 36 rabbits,then BMSCs in combination with wrapped-core structure composite scaffold (group A) and BMSCs in combination with PLGA/β-TCP skeleton (group B) were transplanted into the untreated radial defect as blank control group (group C).12,24 and 48 weeks after implantation,12 animals were sacrificed and the constructs were harvested and analyzed.Results In group A,synosteosis formed between the two ends of the critical-size bone defect 12 weeks postoperation; bone integrity was almost finished and bone marrow started a trend of recanalization 24 weeks postoperation ; bone defect repair was completed and bone marrow was recanalized 48 weeks later.As compared with group B (1,4,6 points),and group C (0,0,1point),Lane-Sandhu indicated that the new bone formation in group A (5,8,and 12 points) was significantly increased (P ＜ 0.05,n =4).Conclusion The combination of BMSCs and core-sheath structure composite scaffold exhibits a favorable osteogenesis,biocompatibility and biodegradability during the repair of autologous segmental radial defect model,which clearly demonstrates promise for the treatment of bone defects through tissue engineering. Key words: Wrapped-core structure composite scaffold;  Bone mesenchymal stem cells;  Segmental bone defects;  Bone tissue engineering