可注射性纳米羟基磷灰石/壳聚糖复合骨髓间充质干细胞促进骨缺损的修复

Injectable nano-hydroxyapatite/chitosan combined with bone marrow stromal cells for repair of bone defects

背景:可注射性纳米羟基磷灰石/壳聚糖复合材料是清华大学利用仿生学原理制备的一种较理想的组织工程新型材料,经过前期体外实验证明其具有良好的生物相容性和骨传导性。目的:观察骨髓间充质干细胞复合可注射性纳米羟基磷灰石/壳聚糖材料在促进骨缺损修复中的作用。方法:用梯度离心和贴壁培养法收集兔骨髓间充质干细胞,分离、培养至第3代,然后与纳米羟基磷灰石/壳聚糖复合。24只新西兰大白兔双侧股骨外侧髁钻孔,制备骨缺损模型。所有兔右侧股骨外侧髁缺损以骨髓间充质干细胞-纳米羟基磷灰石/壳聚糖局部植入作为实验组,其中20只兔左侧股骨外侧髁缺损以单纯纳米羟基磷灰石植入治疗作为对照组,4只兔左侧股骨外侧髁缺损旷置为空白组,于第12周末,分别行大体、影像学观察、组织形态学、观察该复合材料对兔骨缺损的修复效果。结果与结论:术后12周实验组植入体已与骨缺损处骨性愈合,明显见新生骨生成,骨缺损能够完全修复,对照组骨缺损处部分修复,部分骨皮质不连续。空白组缺损区尚未见修复,纤维结缔组织填充。术后12周,实验组见骨形成细胞较多,材料内见新生骨小梁相互连接成片;对照组少量骨细胞形成,骨量少,部分纤维组织填充。空白组未见骨形成细胞,纤维组织较多。结果表明,骨髓间充质干细胞-纳米羟基磷灰石/壳聚糖复合材料具有骨缺损修复能力,其疗效优于单纯纳米羟基磷灰石材料。

BACKGROUND：Injectable nano-hydroxyapatite/chitosan（nano-HA/CS） composite is an ideal tissue engineering new material manufactured by Tsinghua University using bionics principles,previous in vitro experiments have demonstrated their good biocompatibility and bone conduction.OBJECTIVE：To study the ability of bone marrow stromal cells（BMSCs） combined with injectable nano-HA/CS to repair large bone defects of rabbit femoral condyle.METHODS：Rabbit BMSCs were isolated and cultured with density gradient centrifugation method and adhesive culture method.The third generation of BMSCs mixed with nHA/CS.Bone defects were produced by drilling holes in the femoral lateral condyle in each of 24 New Zealand white rabbits.All the right femoral lateral condyle defects were filled with the BMSCs-nHA/CS composite,as treatment group,while 20 of the left side bone defects were filled with nHA alone,as control group.The other 4 rabbits of the left side bone defects were untreated,as blank control group.The ability of repairing rabbit bone defects was evaluated by gross observation,X-ray,histopathological at the end of 12 weeks after operation.RESULTS AND CONCLUSION：In treatment group,the implant achieved bone union with bone defects,with obvious new bone formation,and bone defects were repaired completely.In control group,bone defects were repaired partly,with some nonunion.In the blank control group,no osteogenesis was found in the defect area and the defects were filled with fibrous connective tissue.The new formed bone in the treatment group was confirmed integral and trabecular-like structure was formed after 12 weeks,while a little of new bone formed in the control group,some connective tissues grew into the defect.There were no bone formation cells and many fibrous tissues in blank control group.Results showed that,BMSCs-nHA/CS is effective in repairing bone defects than the nHA.