Division of Materials Technology, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore, Singapore.
Acta Biomater. 2012 Feb;8(2):531-9. doi: 10.1016/j.actbio.2011.09.029. Epub 2011 Sep 28.
The engineering of tissue is preferably done with stem cells, which can be differentiated into the tissue of interest using biochemical or physical cues. While much effort has been focused on using biological factors to regulate stem cell differentiation, recently interest in the contribution of physical factors has increased. In this work, three-dimensional (3-D) microchannels with topographic micropatterns were fabricated by femtosecond laser machining on a biodegradable polymer (poly(L-lactide-co-ε-caprolactone)) substrate. Two substrates with narrow and wide channels respectively were created. Human mesenchymal stem cells (hMSCs) were cultured on the scaffolds for cell proliferation and cellular organization. Gene expression and the immunostaining of myogenic and neurogenic markers were studied. Both scaffolds improved the cell alignment along the channels as compared to the control group. Microfilaments within hMSCs were more significantly aligned and elongated on the narrower microchannels. The gene expression study revealed significant up-regulation of several hallmark markers associated with myogenesis for hMSCs cultured on the scaffold with narrow microchannels, while osteogenic and neurogenic markers were down-regulated or remained similar to the control at day 14. Immunostaining of myogen- and neurogen-specific differentiation markers were used to further confirm the specific differentiation towards a myogenic lineage. This study demonstrates that femtosecond laser machining is a versatile tool for generating controllable 3-D microchannels with topographic features that can be used to induce specific myogenic differentiation of hMSCs in vitro, even in the absence of biological factors.
组织工程最好使用干细胞进行，通过生化或物理线索可以将干细胞分化为感兴趣的组织。虽然人们已经投入大量精力研究使用生物因素来调节干细胞分化，但最近对物理因素贡献的兴趣有所增加。在这项工作中，通过飞秒激光加工在可生物降解聚合物（聚（L-丙交酯-共-ε-己内酯））基底上制造了具有形貌微图案的三维（3-D）微通道。分别创建了具有窄通道和宽通道的两种基底。将人骨髓间充质干细胞（hMSCs）培养在支架上以进行细胞增殖和细胞组织。研究了基因表达和肌源性和神经源性标志物的免疫染色。与对照组相比，两种支架都改善了细胞沿着通道的排列。与较宽的微通道相比，hMSCs 内的微丝在较窄的微通道上排列得更整齐和更长。基因表达研究表明，与在具有窄微通道的支架上培养的 hMSCs 相关的几种与肌生成相关的标志性基因表达显著上调，而成骨和神经生成标志物的表达下调或与对照组相似在第 14 天。使用肌源性和神经源性特异性分化标志物的免疫染色进一步证实了向肌源性谱系的特定分化。这项研究表明，飞秒激光加工是一种通用工具，可用于生成具有形貌特征的可控 3-D 微通道，这些微通道可用于体外诱导 hMSCs 的特定肌源性分化，即使在没有生物因素的情况下也是如此。
