Osteogenesis in transplantation of tissue engineered bone to repair segmental defect of long bone / 中华骨科杂志

ABSTRACT

Objective To investigate the ability of osteogenesis, repaired effects and possible mechanism of tissue engineered bone made in an approach of bionics as a transplantation biomaterial to repair a segmental defect of long bone. Methods HA/?-TCP was composed with PDLLA and then composed with rhBMP-2 and collagen of typeⅠ. The combined biomaterial was put in common culture with osteoblasts harvested from periosteum of rabbit and vascular endothelial cells from kidney of rabbit then transplanted this tissue engineered bone to total segmental periosteum-bone defect of 1.5 cm in the rabbits radius which were investigated 4, 8 and 12 weeks after operation respectively. Investigation of the bone defect was made by means of gross observation, X-ray examination, histology of HE and Masson staining, image pattern analysis, scanning electron microscopy, EDAX. Results In gross observation, the implantations were adhered to the host bone well in four weeks, the implantations was bony healed with host bone in eight weeks, and some of the implantations were replaced by new formation bone in 12 weeks. In histological examination of four weeks after operation, lamellar bone was found, and eight weeks after operation, implant was incorporated to host bone end by end through cortical bone, and new bone marrow was found to invade into the implant. Furthermore, the outer part of implant was completely substituted by new cortical bone 12 weeks after operation. In addition, the histological study pointed out that the new bone arranged in type of various bands which were in subsequent transition. There is significant difference between 4 weeks and 8 weeks, and 4 weeks and 12 weeks, but no significant difference between 8 weeks and 12 weeks of the quantity of new bone. The ratio of calcium to phosphorus in the transplants tended to approach that in the host cortical bone along with the period of time after operation. Conclusion Satisfied effects of remodeling appeared after this tissue engineered bone composed by bionics was transplanted to the segmental defect of long bone. The mechanism of bone regeneration was endochondral ossification.