脂肪基质细胞构建组织工程骨修复下颌骨缺损的实验研究

背景：以往实验认为,只有经过成骨诱导后的脂肪基质细胞才能作为骨组织工程的种子细胞。然而成骨诱导周期过程复杂,延长了细胞体外培养时间和花费。目的：探讨未经过成骨诱导的犬脂肪基质细胞作为种子细胞,利用组织工程技术修复犬下颌骨缺损的可行性。方法：取12个月龄犬背部皮下脂肪,经胶原酶消化法获得单个核细胞,将培养的第3代细胞与双相磷酸钙陶瓷形成支架复合物。在犬下颌骨两侧制备长20mm、高10mm的箱状缺损,拔除缺损区牙齿,分别植入细胞支架复合物和单纯双相磷酸钙陶瓷支架,不进行干预的区域作为空白对照。植入后4周及8周经组织学检测骨缺损修复情况。结果与结论：支架植入后4周,部分支架材料降解,缺损区形成新生骨,双相磷酸钙陶瓷组成骨量明显少于细胞支架复合物组,形成少量新骨及部分新生血管。8周时,两组形成更多的新骨,广泛分布于骨缺损区域,但双相磷酸钙陶瓷组仍明显少于细胞支架复合物组,差异有显著性意义（P〈0.01）。提示脂肪基质细胞复合双相磷酸钙陶瓷可在体内成骨,不经过体外成骨诱导的脂肪基质细胞作为种子细胞,利用组织工程技术可修复下颌骨缺损。

Experimental research on adipose-derived stromal cells in tissue engineering bone for the repair of canine mandibular bone defects

BACKGROUND：Previous studies demonstrated that only adipose-derived stromal cells（ADSCs） after osteogenic induction can be served as seeding cells for bone tissue engineering.However,the process of osteogenic induction is complicated,making the procedure expensive and elongating the culture time in vitro.OBJECTIVE：To explore the feasibility of repairing the canine mandibular bone defects with tissue engineering method based on non-osteogenically induced ADSCs as seeding cells.METHODS：The subcutaneous fat from the back of dogs aged 12 months were obtained,mononuclearcell was obtained by collagenase digestion method.The cultured 3rd passage cells and biphasic calcium phosphate（BCP） ceramics formed scaffold composite.20 mm in length and 10 mm in height of box-like bone defects were prepared in both sides of canine mandibular;the teeth were extracted in defect region.The cell-scaffold composite and BCP ceramics scaffold were implanted in canine mandibular bone defects.The region without intervention served as control.The repair of bone defects was detected by histology,at 4 weeks and 8 weeks implantation.RESULTS AND CONCLUSION：After 4 weeks scaffold implantation,part of scaffold materials was degraded;new bone was formed in defect region.The bone formation in BCP group was significantly less than that in cell-scaffold composite group,and formed a small amount of new bones and part of the new vessels.At 8 weeks scaffold implantation,more new bones were formed between BCP group and cell-scaffold composite group,which were widely distributed in the bone defect region.However,the new bones in BCP group were still significantly less than that in cell-scaffold composite group;there were significant differences（P 0.01）.It is indicated that ADSCs combine with BCP can promote bone formation in vivo.ADSCs-scaffold construct can promote bone formation in vivo.Non-osteogenically induced ADSCs can be used as seed cells to repair the mandibular bone defects by tissue engineering technology.