OBJECTIVETo reconstruct mandibular defect using tissue engineering bone with bone marrow stem cells (BMSCs) cell sheets and investigate the effect of cell sheets on osteogenesis.

METHODSBMSCs were isolated with the method of density gradient centrifugation from canine and cultured. BMSCs were induced to differentiate to osteoblasts. BMSCs induced were fabricated to BMSCs cell sheets. The poly (lactic-co-glycolic acid) (PLGA) wrapped with cell sheets were implanted into the mandibular defect in the left side (experimental side). PLGA wrapped without cell sheets were implanted into the right side (control side) of mandibles. 16 dogs were evenly divided into 4 groups, and one group of them was executed in 4, 8, 12, 16 weeks for gross investigation and histological observation.

RESULTSThe osteogenesis of experimental side was better than that of control side. 16 weeks after implantation, most areas of the mandibular defect were replaced by fresh bone tissue. Compact bone similar to normal bone tissue formed in the lingual defect of mandible and had bony union with the bone stump. The optical density of the fresh bone in the experimental side was higher than that of the control side, there was a significant difference between the two methods (P<0.05). Plenty of lamellar bones formed in experimental side and Haversian system, as well as red marrow, were observed.

CONCLUSIONTissue engineering bone with the structure of lamellar bones can be formed by the technology of BMSCs cell sheets.