表面改性双相陶瓷复合自体骨髓干细胞修复兔骨缺损的实验研究

目的:应用自体骨髓基质干细胞(Bone Marrow Stromal Cells,BMSCs)复合经低晶态羟基磷灰石(Low Crystalline Hydroxyap- atite,LcHA)涂层的双相陶瓷(Biphasic Calcium Phosphate,BCP)构建的组织工程化骨(LcBCP)修复兔桡骨节段性缺损。方法:体外分离培养、诱导扩增兔BMSCs,取第三代细胞复合LcBCP(实验组)后修复15只兔左侧桡骨15mm缺损;右侧桡骨缺损处植入复合BMSCs的BCP(对照组),于植入后4、8和12周处死动物,通过大体形态、组织学、影像学和扫描电镜检测骨缺损修复效果。结果:BMSCs-LcBCP复合物生长良好,随时间延长,X线显示实验组连接处骨痂形成,对照组连接处始终愈合稍差,12周大体观察实验组骨修复良好,髓腔再通;组织学显示板层骨形成,连接处骨性愈合,实验对照组连接处虽然也为骨性愈合,但尚有较多编织骨形成。结论:自体BMSCs复合LcBCP形成的组织工程化骨可修复兔桡骨节段性缺损,低晶态羟基磷灰石涂层能够增强双相陶瓷的早期成骨。

Experimental Study on Repairing of Radial Bone Defects of Rabbits by Implantation of BMSCs and Biphasic Ceramics Coated with Low Crystalline Hydroxyapatite

Objective:To repair segmental radial defects with autogenous bone marrow stromal cells(BMSCs)and biphasic ceramics(Biphasic Calcium Phosphate=BCP)coated with low crystalline hydroxyapatite(LcHA).Methods:BMSCs were expanded and osteogenically induced in vitro.30 healthy adult rabbits were selected.Among them,15 rabbits were randomly chosen (30 radial bones defects models were made),every 15mm-segmental-radial defect in left radii was implanted BMSCs and LcBCP (experimental group,LcBCP group); BMSCs and BCP was implanted into every 15mm-segrnental-radial defect in right radii (control group,BCPgroup).From the rest,3 rabbits were randomly selected and operatively made into bones defects models(blank group),without implantation of any repairing materials.The engineered bones were evaluated by X-ray,SEM,gross and histological examination at 4,8,12 weeks after operation respectively.Results:BMSCs grew well on the LcBCP.X-ray and SEM images showed there was better callus formation at connection sites in experimental group than that in control group.12 weeks after operation in experimental group,the defects were repaired well; recanalization of the marrow cavities were observed; histologically, there were bony healing and lamellar bone formation.while there was more woven bone formation in control group.Conclusions: Rabbits,segmental radial defects can be ultimately repaired with the tissue-engineered bone generated by autogenous osteogenic BMSCs and LcBCP ; Low crystalline hydroxyapatite coatings can enhance bone formation of biphasic ceramics in early stage.