Characterizing Multiscale Mechanical Properties of Brain Tissue Using Atomic Force Microscopy, Impact Indentation, and Rheometry
Characterizing Multiscale Mechanical Properties of Brain Tissue Using Atomic Force Microscopy, Impact Indentation, and Rheometry
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DOI：
10.3791/54201
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发表时间：
2016-09-01
影响因子：
1.2
通讯作者：
Van Vliet, Krystyn J.
中科院分区：
文献类型：
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作者：
Canovic, Elizabeth Peruski;Qing, Bo;Van Vliet, Krystyn J.
为了设计和工程受大脑特性启发的材料，无论是用于机械模拟还是用于组织再生研究，脑组织本身必须在不同的长度和时间尺度上得到很好的表征。与许多生物组织一样，脑组织表现出复杂的分层结构。然而，与大多数其他组织相比，大脑的机械刚度非常低，杨氏弹性模量 E 约为数百帕。这种低刚度可能对关键机械性能的实验表征提出挑战。在这里，我们展示了几种机械表征技术，这些技术适用于测量水合、顺应性生物材料（例如脑组织）在不同长度尺度和加载速率下的弹性和粘弹性特性。在微观尺度上，我们使用原子力显微镜压痕进行蠕变柔量和力松弛实验。在介观尺度上，我们使用基于摆的仪器压头进行冲击压痕实验。在宏观尺度上，我们进行平行板流变测量来量化频率相关的剪切弹性模量。我们还讨论了与每种方法相关的挑战和局限性。这些技术共同实现了脑组织的深入机械表征，可用于更好地了解大脑结构并设计仿生材料。
To design and engineer materials inspired by the properties of the brain, whether for mechanical simulants or for tissue regeneration studies, the brain tissue itself must be well characterized at various length and time scales. Like many biological tissues, brain tissue exhibits a complex, hierarchical structure. However, in contrast to most other tissues, brain is of very low mechanical stiffness, with Young's elastic moduli E on the order of 100s of Pa. This low stiffness can present challenges to experimental characterization of key mechanical properties. Here, we demonstrate several mechanical characterization techniques that have been adapted to measure the elastic and viscoelastic properties of hydrated, compliant biological materials such as brain tissue, at different length scales and loading rates. At the microscale, we conduct creep-compliance and force relaxation experiments using atomic force microscope-enabled indentation. At the mesoscale, we perform impact indentation experiments using a pendulum-based instrumented indenter. At the macroscale, we conduct parallel plate rheometry to quantify the frequency dependent shear elastic moduli. We also discuss the challenges and limitations associated with each method. Together these techniques enable an in-depth mechanical characterization of brain tissue that can be used to better understand the structure of brain and to engineer bio-inspired materials.