人骨髓间质干细胞作为骨、软骨组织工程种子细胞的实验研究

目的 :探讨经体外扩增、诱导分化的人骨髓间质干细胞(humanbonemarrowmesenchymalstemcells,hMSC)作为组织工程化骨、软骨种子细胞的可行性。方法 :体外分离、培养、扩增hMSC ,以流式细胞仪检测hMSC的表面抗原。诱导hMSC向成骨细胞、软骨细胞分化。以倒置显微镜和电子显微镜观察细胞的形态 ;以组织化学、免疫组织化学和RT PCR ,检测成骨细胞、软骨细胞的特异性标志物。结果 :分离得到的细胞可表达hMSC的特异抗原 ,在体外扩增 15代以上 ,其形态及表面抗原保持不变。成骨诱导培养的细胞上清液中ALP的含量高于对照组 (P <0 .0 5 )。成骨及成软骨诱导的细胞形态均由成纤维样梭形向多边形转变。透射电镜观察可见大量扩张的粗面内质网、高尔基体及线粒体。扫描电镜观察可见经成骨诱导后的细胞表面有钙盐沉积 ,成软骨诱导的细胞表面有胶原样突起。成骨诱导培养后 ,可见碱性磷酸酶 (ALP)染色、Ca结节染色、胶原 Ⅰ (COL Ⅰ )及骨钙素 (osteocalcin ,OC)免疫组化染色阳性 ,同时RT PCR检测COL Ⅰ、OCmRNA表达阳性。成软骨诱导后 ,甲苯胺蓝染色见细胞周围有大量的异染性基质 ,免疫组化和RT PCR检测COL Ⅱ表达阳性。结论 :hMSC在体外可大量扩增。在特定培养液诱导下 ,可向成骨细胞及软骨细胞转化 ,可作为骨、软骨组

Experimental research using human bone marrow mesenchymal stem cells as the seed cells for bone and cartilage tissue engineering

AIM: To investigate the feasibility of human bone marrow mesenchymal stem cells(hMSCs) as the seed cells for bone and cartilage tissue engineering. METHODS: Purified hMSCs were cultured in-vitro and induced to differentiate into osteoblasts and chondrocytes. Cellular morphologies were observed under inverted and electron microscopes. The specific markers of the osteoblasts and chondrocytes were detected by histochemical staining, immunohistochemical staining, and RT-PCR. RESULTS: After the hMSCs were passaged for 15 generations, the choractenistic morphology and cell surface antigens of hMSCs remained unchanged. The level of alkaline phosphatase(ALP) in the culture supernatant of the osteoinduction groups was higher than those in the control groups (P<0.05). The morphology of the cells in the osteoinduction and chondroinduction groups changed from spindle-shaped cells into polygon-shaped cells. A large number of the dilated rough endoplasmic reticulua, Golgi apparatus and mitochondria could be seen under transmission electron microscope. Calcium deposition was detected on the surfaces of the hMSCs after osteoinduction. Collagen(COL)-like processes were detected under scanning electron microscope. The staining of the ALP, calcium nudis, COL-I and osteocalcin(OC) were positive, and expressions of the COL-I and OC mRNAs were detected after osteoinduction. The expression of COL-II was detected by immunohistochemical staining and RT-PCR and a lot of the metachromatic-staining matrix around the cells was observed with toluidine blue staining after chondroinduction. CONCLUSION: hMSCs from human bone marrow can be purified, expanded and differentiated into osteoblasts and chondrocytes in-vitro, providing an alternative source for bone and cartilage tissue engineering.