Rossetti L, Kuntz L A, Kunold E, Schock J, Müller K W, Grabmayr H, Stolberg-Stolberg J, Pfeiffer F, Sieber S A, Burgkart R, Bausch A R
Lehrstuhl für Zellbiophysik, Technische Universität München, D-85748 Garching, Germany.
Klinik für Orthopädie und Sportorthopädie, Klinikum rechts der Isar, Technische Universität München, D-81675 München, Germany.
Nat Mater. 2017 Jun;16(6):664-670. doi: 10.1038/nmat4863. Epub 2017 Feb 27.
The exceptional mechanical properties of the load-bearing connection of tendon to bone rely on an intricate interplay of its biomolecular composition, microstructure and micromechanics. Here we identify that the Achilles tendon-bone insertion is characterized by an interface region of ∼500 μm with a distinct fibre organization and biomolecular composition. Within this region, we identify a heterogeneous mechanical response by micromechanical testing coupled with multiscale confocal microscopy. This leads to localized strains that can be larger than the remotely applied strain. The subset of fibres that sustain the majority of loading in the interface area changes with the angle of force application. Proteomic analysis detects enrichment of 22 proteins in the interfacial region that are predominantly involved in cartilage and skeletal development as well as proteoglycan metabolism. The presented mechanisms mark a guideline for further biomimetic strategies to rationally design hard-soft interfaces.
肌腱与骨骼的承重连接所具有的卓越力学性能依赖于其生物分子组成、微观结构和微观力学之间复杂的相互作用。在此，我们确定跟腱与骨的插入处的特征是存在一个约500μm的界面区域，该区域具有独特的纤维组织和生物分子组成。在这个区域内，我们通过微观力学测试结合多尺度共聚焦显微镜确定了一种非均匀的力学响应。这导致局部应变可能大于远程施加的应变。在界面区域承受大部分载荷的纤维子集随力的施加角度而变化。蛋白质组学分析检测到界面区域有22种蛋白质富集，这些蛋白质主要参与软骨和骨骼发育以及蛋白聚糖代谢。所提出的机制为进一步合理设计硬-软界面的仿生策略提供了指导方针。
