An in situ study of collagen self-assembly processes
An in situ study of collagen self-assembly processes
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DOI：
10.1021/bm700973t
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发表时间：
2008-01-01
影响因子：
6.2
通讯作者：
Pfohl, Thomas
中科院分区：
文献类型：
--
作者：
Koester, Sarah;Evans, Heather M.;Pfohl, Thomas
我们对微流体装置中半稀溶液中胶原凝胶的自组装和动态演化进行了原位研究。胶原纤维不仅增强骨骼和组织的机械性能，而且还影响细胞运动和形态。我们通过使用流体动力聚焦形成定向纤维来实现胶原原纤维和网络分层自组装的初始步骤。准确描述微通道内的条件需要设备中 pH 值的数值表达式以及粘度的修改数学描述，当胶原纤维在中性 pH 值附近形成时，粘度会增加近 300 倍。有限元建模轮廓与通道中双折射原纤维的交叉偏光显微镜图像令人印象深刻地重叠。流动中的实时 X 射线微衍射测量表明增强的超分子堆积，其单位间距与五聚胶原亚基的单位间距相当。这些结果对生物医学领域具有重大意义，其中对新型排列、细胞活性和机械强化材料的需求持续增长。然而，从更基本的生物物理学角度来看，这项工作也很引人注目，因为基本概念可以推广到大量系统。
We present in situ studies on the self-assembly and,dynamic evolution of collagen gels from semidilute solutions in a microfluidic device. Collagen fibrils not only reinforce the mechanical properties of bone and tissues, but they also influence cellular motility and morphology. We access the initial steps of the hierarchical self-assembly of collagen fibrils and networks by using hydrodynamic focusing to form oriented fibers. The accurate description of the conditions within the microchannel requires a numerical expression for the pH in the device as well as a modified mathematical description of the viscosity, which increases nearly 300-fold as collagen fibrils form around neutral pH. Finite element modeling profiles overlay impressively with cross-polarized microscopy images of the birefringent fibrils in the channel. Real-time X-ray microdiffraction measurements in flow indicate an enhanced supramolecular packing having a unit spacing commensurate with that of a pentameric collagen subunit. These results have significant implications for the field of biomedicine, wherein new aligned, cellularly active, and mechanically strengthened materials continue to be in demand. However, this work is also-remarkable from a more fundamental, biophysical point of view because the underlying concepts may be generalized to a large pool of systems.