Construction of calcium sulfate/bone marrow mesenchymal stem cells tissue-engineered bone for spinal fusion / 中国组织工程研究

ABSTRACT

BACKGROUND:Calcium sulfate has good biocompatibility and biodegradability, which is a safe and effective bone graft substitute. OBJECTIVE:To investigate the osteogenesis ability of calcium sulfate combined with bone marrow mesenchymal stem cells. METHODS:After L4/5 posterior lumbar discectomy, 36 rabbits were randomized into three groupsrabbits in autologous bone group were implanted with autologous iliac bone via the intervertebral space;animals in al ogenic bone group were implanted with decalcified bovine bone;rabbits in tissue-engineered bone group were implanted with calcium sulfate combined with bone marrow mesenchymal stem cells. Bone formation and molding were observed by gross observation, anteroposterior and lateral X-ray, histology and biomechanics at 4, 8 and 16 weeks. Cal us specimens were employed for histological observation of interbody fusion. Biomechanical analysis of spinal fusion site was conducted at 16 weeks. RESULTS AND CONCLUSION:Sixteen weeks later, interbody fusion was complete in the autologous bone group, the trabecular bone bridged continuously and a large amount of woven bone was merged into pieces;in the al ogenic bone group, incomplete bony fusion was found between the intervertebral space, most of cartilage tissues differentiated into bone, but fibrous tissue was also ful of the central part;in the tissue-engineered bone group, interbody fusion was complete, and a large amount of woven bone was fused into pieces, while the artificial bone was absorbed and ossified with smal residual. Failure strength and stiffness in the autologous bone and tissue-engineered bone groups were superior to those in the al ogenic bone group. These findings indicate that the calcium sulfate/bone marrow mesenchymal stem cells tissue-engineered bone has excellent osteogenic and osteoinductive capacity that can exert a good function of promoting spinal interbody fusion.