Understanding the Stiff-to-Compliant Transition of the Meniscal Attachments by Spatial Correlation of Composition, Structure, and Mechanics
Understanding the Stiff-to-Compliant Transition of the Meniscal Attachments by Spatial Correlation of Composition, Structure, and Mechanics
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DOI：
10.1021/acsami.9b03595
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发表时间：
2019-07-31
影响因子：
9.5
通讯作者：
Bonassar, Lawrence J.
中科院分区：
文献类型：
--
作者：
Boys, Alexander J.;Kunitake, Jennie A. M. R.;Bonassar, Lawrence J.
最近，科学界已经表现出相当大的兴趣，在工程组织有组织的组成和结构梯度，以模仿硬到软组织界面。这一努力受到阻碍的天然组织界面的建设的不完整的理解。在这项工作中，我们结合了拉曼显微镜和共聚焦弹性成像映射的成分，结构和机械特性，在膝盖半月板附件的刚性顺应性界面。这项研究提供了新的见解的方法，生物介导的刚度超过几十微米的多个数量级的变化。我们确定了纳米到中尺度的结构如何介导界面上复杂的微尺度过渡区域：两个由化学成分定义的区域，五个由结构特征区分的区域，以及三个机械上不同的区域。我们确定了三个主要组成部分，导致一个强大的软组织和骨之间的界面：移动的胶原纤维单位，连续的界面区域，和局部刚度梯度。这种组织结构允许附件中的胶原纤维发生大位移，从而实现半月板运动，而不会使软组织与骨界面产生局部应变。这些区域的相互作用揭示了一种方法，该方法依赖于跨多个长度尺度的分层结构，以最大限度地减少高度不同材料之间的应力集中。这些见解激发了合成软组织-骨附着体和仿生材料界面的新设计策略。
Recently, the scientific community has shown considerable interest in engineering tissues with organized compositional and structural gradients to mimic hard-to-soft tissue interfaces. This effort is hindered by an incomplete understanding of the construction of native tissue interfaces. In this work, we combined Raman microscopy and confocal elastography to map compositional, structural, and mechanical features across the stiff-to-compliant interface of the attachments of the meniscus in the knee. This study provides new insight into the methods by which biology mediates multiple orders of magnitude changes in stiffness over tens of microns. We identified how the nano- to mesoscale architecture mediates complex microscale transitional regions across the interface: two regions defined by chemical composition, five distinguished by structural features, and three mechanically distinct regions. We identified three major components that lead to a robust interface between a soft tissue and bone: mobile collagen fiber units, a continuous interfacial region, and a local stiffness gradient. This tissue architecture allows for large displacements of collagen fibers in the attachments, enabling meniscal movement without localizing strains to the soft tissue-to-bone interface. The interplay of these regions reveals a method relying on hierarchical structuring across multiple length scales to minimize stress concentrators between highly dissimilar materials. These insights inspire new design strategies for synthetic soft tissue-to-bone attachments and biomimetic material interfaces.