Bone barrow mesenchymal stem cells in conjunction with bone morphOgenetic protein promote spine interbody fusion in rabbits / 中国组织工程研究

ABSTRACT

BACKGROUND: Several studies have demonstrated that bone marrow mcscnchymal stem cells (MSCs) can differentiate into osteoblasts after induction of bone morphogenetic protein (BMP).OBJECTIVE: This study was designed to compare the osteogenetic effects between MSCs, bBMP, and fibrin gel alone and their composite.DESIGN: A controlled observation experiment.SETTING: Second People's Hospital of Guangdong Province and Second Hospital Affiliated to Sun Yat-sen University.MATERIALS This study was performed at the Second Hospital Affiliated to Sun Yat-sen University between January 2004 and June 2006. Healthy New Zealand rabbits were provided by the Laboratory Animal Center, Sun Yat-sen University.METHODS: Bone marrow was taken from the lilac bone. By density gradient centrifugation, autologous MSCs were in vitro cultured and amplified. A composite was made of fibrin gel and bovine bone morphogenetic protein (bBMP). After adding MSCs, another composite was made. Twelve rabbits underwent lumbar L3/4, LA/5, and LS/6 discectomy and interbody fusion via an anterior retroperitoneal approach. Three fusion sites in each animal were randomly assigned into three of four treatments composite of MSCs and hBMP and fibrin gel (group A), composite of MSCs and fibrin gel (group B), composite of bBMP and fibrin gel (group C) and fibrin gel alone (group D). The interbodies were observed radiologically and histologically 3 months after surgery.MAIN OUTCOME MEASURES: Bone formation in the spinal interveRebral space of rabbits.RESULTS: Twelve weeks after surgery, bone formation was appasenfly greater in the Group A than in the other groups.Histological findings revealed continuous bone formation. The groups B and C showed equivalent radiological and histological changes. Bone formation was intermittent. Group D had fibrous union, but no bone formation. No residual fibrin gel was found in all groups, but a small amount of residual nucleus gelatinosus with a little cartilaginous tissue was visible in the intervertebral disc.X-ray examination results did not reveal vertebral posterior hyperplasia or spinal stenosis. There was significant difference in range of lumbar motion between the group B and the groups C and D (P ＜ 0.05). No pronounced difference in vertebral posterior height loss existed among the groups.CONCLUSION: The composite of MSCs, fibrin gel and bBMP can promote bone regeneration and achieve osseous spinal fusion.