Bone marrow mesenchymal stem cells/collagen/chitosan combined with bone transport for tibial defect repair：study protocol for a randomized controlled trial / 中国组织工程研究

ABSTRACT

BACKGROUND:Bone marrow mesenchymal stem cels play an osteogenic role under the assistance of scaffold materials. The scaffold cannot only deliver the cels to the bone defect area, but also act as a new bone growth framework. Colagen-chitosan composite is one of ideal scaffold materials in bone tissue engineering, which has osteoinductive ability and better osteogenic ability than conventional scaffolds. Bone transport technology has been widely used in the clinical repair of long bone defects, but it has some deficiencies, such as slow osteogenesis, long time for external fixation and nonunion. How to further accelerate bone formation and reduce complications has become the current problem to be solved. Here, it is hypothesized that bone marrow mesenchymal stem cels/ colagen/chitosan composite scaffold can increase the therapeutic effect of bone transport in the repair of tibial bone defects. METHODS/DESIGN:This study is a randomized controled animal experiment, includingin vitro andin vivo tests.In vitro test Bone marrow mesenchymal stem cels are isolated from the bone marrow of New Zealand rabbits aged 1-2 months, and passaged to the third generation. Then, cel suspension is added onto the colagen-chitosan scaffold to construct the bone marrow mesenchymal stem cels/colagen/chitosan composite scaffold.In vivo test Twenty-four New Zealand rabbits at 3-4 months are selected and randomly assigned to receive bone transport, scaffold implantation, bone transport+scaffold implantation, respectively. The primary outcome measures are the growth of implant materials and bone defect interface, X-ray detection of bone defect repair, hematoxylin-eosin staining and scanning electron microscope observation of bone formation in the bone defect region, immunohistochemical detection of type I colage expression in the osteogenic region, scanning electron microscope observation of interface bonding between implant materials and host bone, ultrastructure and bone formation. DISCUSSION:The results from this animal experiment wil help to determine the feasibility of bone marrow mesenchymal stem cels/colagen/chitosan composite scaffold to accelerate bone repair during bone defect repair using bone transport technology.