Tuning the Elastic Modulus of Hydrated Collagen Fibrils
Tuning the Elastic Modulus of Hydrated Collagen Fibrils
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DOI：
10.1016/j.bpj.2009.09.010
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发表时间：
2009-12-02
影响因子：
3.4
通讯作者：
Thomson, Neil H.
中科院分区：
文献类型：
--
作者：
Grant, Colin A.;Brockwell, David J.;Thomson, Neil H.
溶液条件的系统变化揭示了单个胶原原纤维的弹性模量（E）可以在2-200 MPa的范围内变化。利用原子力显微镜（AFM）对重组牛跟腱原纤维在不同水溶液和乙醇环境下的纳米压痕进行了研究。在pH 7下将一价盐滴定至浓度为1 M，导致E从2 MPa增加至5 MPa。这种硬化效果在较低pH下更明显，其中，在pH 5下，例如，加入1 MKCl后，模量增加了约7倍。通过使用增加浓度的乙醇，可以实现模量的甚至更大的增加，高达类似于200 MPa。总之，这些结果表明，有一些原胶原单体之间的分子间力，支配弹性反应。这些包括水合力和氢键、离子对，以及可能的疏水效应。调节这些力的相对强度允许合理调节原纤维的弹性模量。
Systematic variation of solution conditions reveals that the elastic modulus (E) of individual collagen fibrils can be varied over a range of 2-200 MPa. Nanoindentation of reconstituted bovine Achilles tendon fibrils by atomic force microscopy (AFM) under different aqueous and ethanol environments was carried out. Titration of monovalent salts up to a concentration of 1 M at pH 7 causes E to increase from 2 to 5 MPa. This stiffening effect is more pronounced at lower pH where, at pH 5, e.g., there is an similar to 7-fold increase in modulus on addition of 1 M KCI. An even larger increase in modulus, up to similar to 200 MPa, can be achieved by using increasing concentrations of ethanol. Taken together, these results indicate that there are a number of intermolecular forces between tropocollagen monomers that govern the elastic response. These include hydration forces and hydrogen bonding, ion pairs, and possibly the hydrophobic effect. Tuning of the relative strengths of these forces allows rational tuning of the elastic modulus of the fibrils.