骨髓基质干细胞联合血管束植入构筑血管化组织工程骨修复兔大段骨缺损

Repair of large segmental bone defects with vascularized bone in rabbits

目的研究兔骨髓基质干细胞（BMSCs）联合动静脉血管束植入异种脱蛋白松质骨（XDCB）构筑血管化组织工程骨修复兔桡骨中远段完全骨膜骨缺损的能力。方法从兔髂嵴抽骨髓培养制备免BMSCs，将第5代BMSCs种植于多孔XDCB并进行成骨诱导2周制备组织工程骨，手术中分离兔桡动、静脉血管束。动物模型为制备24只兔双侧桡骨中远段完全骨膜骨缺损1．5cm共48侧，分4组修复（n=12），A组为空白术治疗组，B组为单纯材料＋血管束植入组（XDCB＋VB），C组为组织工程骨组（XDCB＋BMSCs），D组为组织工程骨＋血管束植入组（XDCB＋BMSCs＋VB），各组交叉配对。分别于术后4、8、12周行X线片、大体解剖、组织切片、生物力学等检查，观察各组骨缺损修复效能及移植物血管化情况。结果D组骨缺损修复效能（术后12周新骨面积比2．02％±0．16％）及血管化情况（术后12周血管面积比6．89％±0．32％）优于C组（1．50％±0．28％和3．17％±0．19％），而C组又优于B组（1．59％±0．19％和6．52％±0．23％），A组骨缺损未修复，各组结果差异有统计学意义（P〈0．05）。结论BMSCs联合动静脉血管束植入构筑的血管化组织工程骨能促进成骨过程和新生骨的血管化，显著提高组织工程骨修复大段骨缺损的能力.

Objective To study the effect of vaseularized bone constructed by bone ,narrow stromal cells （BMSCs） combined with vascular bundle implants in porous xenogeneic deproteinised cancellous bone （XDCB） on repairing large segmental bone defects in rabbits. Methods Radius diaphyseal defects of 1.5 cm long were made bilaterally in 24 rabbits. The 48 bone defects were randomized into 4 groups （ n = 12） Group A was repaired without any implants, group B with XDCB and vascular bundle （VB） implants （XDCB ＋ VB）, group C with tissue engineered bone （XDCB ＋ BMSCs）, and group D with vascularized bone （XDCB ＋ BMSCs ＋ VB） . X-ray examination, gross anatomic observation, HE staining of tissue slices of the implants, biomechanical tests of the specimens were carried out 4, 8 and 12 weeks after operation to evaluate the repairing effect and vascularization of the implants. Results The defects in group A showed little trace of bone regeneration. Group D showed a far more extensive effect on bone defect repairing and vascularization of the implant than group C, and group C more than group B （ P 〈 0. 05）. Conclusion Vascularized bone constructed by BMSCs combined with vascular bundle implants in porous XDCB can accelerate the vascularization and osteogenesis process of implant, greatly enhancing the effect on repairing large segmental bone defects in rabbits.