Bones are structurally heterogeneous organs with diverse functions that undergo mechanical stimuli across multiple length scales. Mechanical characterization of the bone microenvironment is important for understanding how bones function in health and disease. Here, we describe the mechanical architecture of cortical bone, the growth plate, metaphysis, and marrow in fresh murine bones, probed using atomic force microscopy in physiological buffer. Both elastic and viscoelastic properties are found to be highly heterogeneous with moduli ranging over three to five orders of magnitude, both within and across regions. All regions include extremely compliant areas, with moduli of a few pascal and viscosities as low as tens of Pa·s. Aging impacts the viscoelasticity of the bone marrow strongly but has a limited effect on the other regions studied. Our approach provides the opportunity to explore the mechanical properties of complex tissues at the length scale relevant to cellular processes and how these impact aging and disease.

中文翻译：

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以原子力显微镜为特征的骨微环境中的机械异质性

骨骼是结构异质的器官，具有不同的功能，可以承受多个长度尺度的机械刺激。骨骼微环境的机械特性对于了解骨骼在健康和疾病中的功能很重要。在这里，我们描述了新鲜鼠骨中皮质骨、生长板、干骺端和骨髓的机械结构，在生理缓冲液中使用原子力显微镜进行探测。发现弹性和粘弹性特性都具有高度异质性，区域内和区域间的模量范围超过三到五个数量级。所有区域都包括极其柔顺的区域，模量只有几帕，粘度低至几十帕·秒。衰老会强烈影响骨髓的粘弹性，但对其他研究区域的影响有限。