骨髓间充质细胞复合胶原-壳聚糖材料联合骨搬移修复胫骨缺损：随机对照实验方案

背景：骨髓间充质干细胞发挥成骨作用需要支架材料的辅助，一方面支架材料不仅可将细胞运载至骨缺损区域，另一方面还可作为新骨生长的框架结构。胶原-壳聚糖复合材料是骨组织工程较为理想的支架材料之一，同时其具有骨诱导性，比常规支架材料更优越的成骨能力。骨搬移技术在临床上在修复长段骨缺损方面已得到广泛应用，但也存在成骨慢、外固定时间长、骨不连等缺憾。如何进一步加快骨形成速度，减少并发症发生，已成当前亟待解决的问题。实验假设：骨髓间充质干细胞复合胶原-壳聚糖支架移植能提高胫骨缺损骨搬移修复效果。 方法/设计：随机对照动物实验。分为体外和体内实验两部分。体外实验中取月龄一两个月的新西兰大白兔股骨骨髓，提取骨髓间充质干细胞，培养至第3代，将细胞悬液滴于胶原-壳聚糖支架材料，构建骨髓间充质干细胞复合胶原-壳聚糖支架。体内实验选用24只三四月龄新西兰大白兔，被随机分配接受如下干预：骨搬移、支架植入、骨搬移联合支架植入。研究的主要观察指标为植入材料与骨缺损界面的生长情况、X射线检测的缺损区骨修复情况、苏木精-伊红染色及扫描电镜观察缺损区成骨情况、免疫组织化学染色检测成骨区Ⅰ型胶原蛋白的表达情况、扫描电子显微镜观察移植材料与宿主骨的界面键合情况、超微结构及新骨的生成。 讨论：实验结果将有助于确定对骨缺损进行骨搬移治疗过程中，应用骨髓间充质干细胞复合胶原-壳聚糖支架移植促进骨缺损再生修复效果的可行性。 实验方案获基金支持情况：获辽宁省科学技术计划项目资助(2012225019)。 中国组织工程研究杂志出版内容重点：干细胞；骨髓干细胞；造血干细胞；脂肪干细胞；肿瘤干细胞；胚胎干细胞；脐带脐血干细胞；干细胞诱导；干细胞分化；组织工程

Bone marrow mesenchymal stem cells/collagen/chitosan combined with bone transport for tibial defect repair: study protocol for a randomized controlled trial

BACKGROUND:Bone marrow mesenchymal stem cells play an osteogenic role under the assistance of scaffold materials. The scaffold cannot only deliver the cells to the bone defect area, but also act as a new bone growth framework. Collagen-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 cells/ collagen/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 controlled animal experiment, including in vitro and in vivo tests. In vitro test: Bone marrow mesenchymal stem cells are isolated from the bone marrow of New Zealand rabbits aged 1-2 months, and passaged to the third generation. Then, cell suspension is added onto the collagen-chitosan scaffold to construct the bone marrow mesenchymal stem cells/collagen/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 collage 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 will help to determine the feasibility of bone marrow mesenchymal stem cells/collagen/chitosan composite scaffold to accelerate bone repair during bone defect repair using bone transport technology.