ABSTRACT
Objective: To study the effects of tissue engineered bone in the repair of mandibular defect.Methods:The experiments were conducted in 12 dogs.Bone marrow stromal stem cells(BMSCs) of dog were cultured in DMEM containing 100 ml/L fetal bovine serum and induced to differentiate towards osteoblasts.Then the cells were seeded onto absorbable polylactic acid(PLA) compounded with rhBMP-2(0.16 mg for each implant), the composite was implanted into the oval-shaped mandibular bone defect in the size of 30 mm?12 mm on one side,another side was used as blank control.The dogs were divided into 4 grups with 3 in each group.PLA/rhBMP/BMSCs,PLA/rhBMP,PLA/BMSCs and PLA were used as the implants in group A,B,C and D respectively. 2, 4 and 8 weeks after implantation,the effectiveness of bone formation was evaluated by means of gross observation,histological and scanning electronic microscope ( SEM) examination. Results: In group A new bone formation in the implanted defects was observed 4 weeks after operation, the defects were replaced by muture bone tissue 8 weeks after operation. In group B a little new bone was found in the implanted area 4 weeks after operation and fibrous bone was observed 8 weeks after operation. In group C chondral ossification was found and in group D fibrous tissue was found in the bone defects 8 weeks after operation.Conclusion:PLA/rhBMP/BMSCs may be feasible in the repair of bone defect.