三种高分子支架对骨髓基质细胞生长影响的研究

研究高分子复合支架聚乳酸均聚物(PLA)、聚乳酸/聚乙二醇共聚物(PLA-PEG)和聚乳酸/聚乙醇酸共聚物(PLGA)对骨髓基质细胞(M SC)黏附、增殖和分化的影响。分离、纯化兔骨髓基质细胞,分别和3种支架材料共培养。在不同时间段,应用细胞计数,碱性磷酸酶(ALP)定量分析,四环素荧光染色,扫描电镜,RT-PCR的方法,观察细胞在3种材料上生长,黏附和矿化沉积情况。结果表明细胞在3种支架材料上生长良好,PLGA上细胞生长的数量最多,其次是PLA-PEG、PLA,呈时间依赖性增加。3种材料上的细胞均表达ALP活性,PLA-PEG和PLGA组的ALP活性无差异,但显著高于PLA组,差异有显著性。RT-PCR反应可检测到骨钙素和纤维I型胶原在mRNA水平的表达。扫描电镜见细胞最初呈球形附着于材料上,7 d后细胞数量增加并分泌细胞外基质。两周后可见钙化结节形成,四环素荧光呈黄绿色染色。结果提示M SC细胞能较好的黏附于3种聚合物支架上,生长良好,并表达一定的成骨潜能,但PLA共聚物PLA-PEG和PLGA优于PLA均聚物,有望成为较好的构建组织工程骨的支架。

Effect of Polymeric Scaffolds on Attachment and Growth of Bone Marrow Mesenchymal Stem Cells

To investigate the effect of three kinds of polymeric scaffolds on attachment,proliferation and differentiation of bone marrow mesenchymal stem cells,the cells were different polymeric scaffolds of PLA-PEG,PLA,PLGA,respectively.The proliferation of cell was evaluated by cell count;the attachment and morphology of BMSCs were observed by SEM;and differentiation was detected by alkaline phosphatase activity,fluorescence,and RT-PCR methods.Results showed that the cells in PLGA group spread better among BMSCs adhered to the three polymeric scaffolds.The activity of ALP was detected after 3 days culture in these three groups.There were no significant differences between PLA-PEG and PLGA groups,but the activity of ALP was higher than PLA group.The gene expressions of osteocalicin and collagen I were also observed in the early culture time.Calcium nodes formation in these polymeric scaffolds were detected.BMSC spreading first,then overlapping growth and secretion of matrix around the bottom and surface of scaffolds were observed through SEM.In summary,PLA-PEG and PLGA are better polymeric scaffolds for the bone tissue engineering,compared with PLA.