The Study Of Repair Scapula Defect In Vivo Allogenic Rabbit With Tissue-engineered Periosteum Constructed

Objective:To investigate the biological characteristics and osteogenic potential of tissue-engineered periosteum which was constructed by bone marrow mesenchymal stem cells (BMSCs) and porcine small intestinal submucosa (SIS).and to investigate the feasibility it(TEP) to repair the large irregular bone defects in allogenic rabbits.Methods:Porcine small intestinal submucosa(SIS) co-cultivated with3th generation osteogenically induced BMSCs in vitro to construct tissue-engineered periosteum. Twenty-four6-month-old New Zealand rabbits whose scapula was incompletely resected to establish one-side large irregular bone defects (3cm×3cm)model. The bone defects were repaired with TEP (experimental group, n=12) and SIS (control group, n=12). At4、8、12weeks after operation, the rabbits were sacrificed, and the implants were harvested. The general condition of the rabbits was observed; X-ray radiography and score, and histological examination (HE staining and Masson staining) were performed.Results:Growth status of seeding cells remains good ontissue-engineered periosteum. ALP activity expression reached peak in the7th day, while osteocalcin quantity in the11th day when tissue-engineered periosteum cultured in osteogenic inducing medium. After operation on different time, The X-ray results showed new bone formation with normal bone density in the defect area of the experimental group; but no bone formation was observed in the control group. On12weeks the general observation of the specimens showed bone healing at both ends of the defect, and the defect was filled by new bone in the experimental group; no new bone formed in the control group. The histological staining showed new bone tissue where there were a lot of new vessels and medullary cavity, and no macrophages or lymphocytes infiltration was observed in the defect area of the experimental group; some connective tissue was found in the control group.Conclusion:The biological characteristics of tissue engineered periosteum remained stable in vitro. The osteogenetic activity of tissue engineered periosteum was higher in the7-11th day after constructed and cultured in osteogenic inducing medium. And it can form new bone in allogenic rabbit and has the feasibility to repair the large irregular bone defects.