ABSTRACT
BACKGROUND: Bone tissue engineering technology brings a new path to treat bone defects, and moreover, gene transfection optimizes the effects of tissue-engineered bone in bone repair. OBJECTIVE: To observe the effect of allogenic bone carrying bone morphogenetic protein-2 (BMP-2) and basic fibroblast growth factor (bFGF) transfected bone marrow mesenchymal stem cells (BMSCs) in the repair of critical-sized bone defects of the sheep ilium. METHODS: Nine Altay sheep were taken to make animal models of critical-sized bone defects in the bilateral ilia. Allogenic bone carrying BMP-2 and bFGF-transfected BMCSCs was implanted into the left side of the ilium (n=9, experimental group), while allogenic bone carrying BMSCs (n=3, cell scaffold group), allogenic bone (n=3, allogenic bone group) and β-tricalcium phosphate (n=3, β-TCP group) were implanted into the right side of the ilium, respectively. Histological observation and immunohistochemical staining were performed at 4, 8, 12 weeks after implantation. RESULTS AND CONCLUSION: Findings from histological observation showed that: at 12 weeks after implantation, the experimental group exhibited obvious bone remodeling, largely absorbed bone allograft, gradually reduced osteoclast-like cells and increased osteoblast-like cells, clear trabecular structure, dense bone matrix around the trabecular bone, and large area of flaky new bone tissues. Bone materials also degraded in the other three groups, but no remodeling occurred. Immunohistochemical staining showed that at 12 weeks after implantation, bone sialoprotein type I collagen in the experimental group were strongly positive, while they were weakly expressed in the remaining three groups. Overall, our findings indicate that the allogenic bone carrying BMP-2 and bFGF-transfected BMSCs can thoroughly repair critical-sized bone defects of the sheep ilium.