Price Joshua C, Roach Paul, El Haj Alicia J
ISTM Guy Hilton Research Centre, Keele University, Thornburrow Drive, Stoke on Trent ST4 7QB, United Kingdom.
ACS Biomater Sci Eng. 2016 Apr 11;2(4):625-633. doi: 10.1021/acsbiomaterials.6b00030. Epub 2016 Mar 25.
This report describes methods for fabricating substrates with anisotropic order from a single solution of high concentration collagen. By exploiting the intrinsic property of collagen to behave as a cholesteric liquid crystal, we demonstrate first the production of dense collagen films containing anisotropic fibers by simple dialysis and polymerization in ammonia vapor. We then utilized shear driven alignment of collagen using viscous extrusion to produce aligned collagen fibers. Next we describe an evaporation technique to observe crystalline growth into the collagen, which serves to template the substrate prior to fibrillogenesis. The ordered substrates supported osteogenic differentiation of hMSCs and also oriented growth of hMSCs. We also demonstrate using Raman spectroscopy that the local protein concentration in the substrates influenced the molecular orientation of collagen, Finally, we compare the resultant textures in the substrates with section of native cornea and tendon using polarized light microscopy, which showed remarkable similarities in terms of both anisotropy and second order chiral structure. These rapid, cost-effective methods could potentially serve a range of different applications in tissue engineering.
本报告描述了从高浓度胶原蛋白单一溶液制备具有各向异性排列的基质的方法。通过利用胶原蛋白作为胆甾型液晶的固有特性，我们首先展示了通过简单透析和在氨蒸气中聚合来生产含有各向异性纤维的致密胶原膜。然后，我们利用粘性挤压对胶原蛋白进行剪切驱动排列，以生产排列的胶原纤维。接下来，我们描述了一种蒸发技术，用于观察晶体在胶原蛋白中的生长，这在原纤维形成之前为基质提供模板。有序基质支持人骨髓间充质干细胞的成骨分化，并使人骨髓间充质干细胞定向生长。我们还使用拉曼光谱证明，基质中的局部蛋白质浓度影响胶原蛋白的分子取向。最后，我们使用偏光显微镜将基质中产生的纹理与天然角膜和肌腱切片进行比较，结果显示在各向异性和二阶手性结构方面都有显著相似性。这些快速、经济高效的方法可能在组织工程中有一系列不同的应用。
