中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2021, Vol. 16 ›› Issue (12): 2557-2562.doi: 10.4103/1673-5374.313059

• 原著:脊髓损伤修复保护与再生 • 上一篇    

创伤性脊髓白质损伤后各向异性和速度依赖性的拉伸力学特性

  

  • 出版日期:2021-12-15 发布日期:2021-05-17
  • 基金资助:

    这项工作得到了日本科学振兴会和山口大学医院（转化促进补助金）的支持

Tensile mechanical analysis of anisotropy and velocity dependence of the spinal cord white matter: a biomechanical study

Norihiro Nishida1, *, Itsuo Sakuramoto2, Yoshihiro Fujii2, Rudolf Yoga Hutama2, Fei Jiang3, Junji Ohgi3, Yasuaki Imajo1, Hidenori Suzuki1, Masahiro Funaba1, Xian Chen3, Takashi Sakai1   

  1. 1Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Minami-Kogushi, Ube, Yamaguchi, Japan; 2Department of Mechanical and Electrical Engineering, National Institute of Technology Tokuyama College, Gakuendai, Shunan, Yamaguchi, Japan; 3Faculty of Engineering, Yamaguchi University, Tokiwadai Ube, Yamaguchi, Japan
  • Online:2021-12-15 Published:2021-05-17
  • Contact: Norihiro Nishida, MD, PhD, nishida3@yamaguchi-u.ac.jp.
  • Supported by:
    This work was supported by the Japan Society for the Promotion of Science (KARENHI grant number JP 15K20002) and by the Yamaguchi University Hospital (a translational promotion grant).

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摘要：

在脊髓损伤中，来自各个方向的外力以不同的速度发生。因此，重要的是要进行物理评估，确定脊髓易受外力伤害并增加内应力。实验假设脊髓具有机械特性，这些机械特性在应力作用下会根据损伤的方向和速度而变化。然而，脊髓非常柔软且难以实验，以前的报道也没有研究多种外力的影响。实验使用牛脊髓白质来测试和分析脊髓的各向异性和外力速度依赖性。对脊髓白质在纤维方向（从头到尾）进行了拉伸-垂直（TV），平行拉伸（TP），垂直剪切（SV）和平行剪切（SP）测试。实验中的应变速率为0.1，1，10和100 / s。实验计算了脊髓的杨氏模量。拉伸和剪切试验的结果显示，当平行于轴突纤维的方向施加外力时，如在平行拉伸和平行剪切中，应力趋于增加。但是，即使在速度增加的情况下，例如在拉伸-垂直和垂直剪切中，沿纤维方向和垂直方向撕裂的外力也不太可能增加应力。实验发现脊髓容易受到外力，特别是在纤维方向上外力的损害；并且当外力的速度增加时，脊髓会承受更大的应力。这些结果证实脊髓损伤程度更取决于外力速度和脊髓的各向异性。

https://orcid.org/0000-0001-7754-6579 (Norihiro Nishida)

Abstract: In spinal cord injuries, external forces from various directions occur at various velocities. Therefore, it is important to physically evaluate whether the spinal cord is susceptible to damage and an increase in internal stress for external forces. We hypothesized that the spinal cord has mechanical features that vary under stress depending on the direction and velocity of injury. However, it is difficult to perform experiment because the spinal cord is very soft. There are no reports on the effects of multiple external forces. In this study, we used bovine spinal cord white matter to test and analyze the anisotropy and velocity dependence of the spinal cord. Tensile-vertical, tensile-parallel, shear-vertical, and shear-parallel tests were performed on the white matter in the fibrous direction (cranial to caudal). Strain rate in the experiment was 0.1, 1, 10, and 100/s. We calculated the Young’s modulus of the spinal cord. Results of the tensile and shear tests revealed that stress tended to increase when external forces were applied parallel to the direction of axon fibers, such as in tensile-vertical and shear-vertical tests. However, external forces those tear against the fibrous direction and vertically, such as in tensile-parallel and shear-parallel tests, were less likely to increase stress even with increased velocity. We found that the spinal cord was prone to external forces, especially in the direction of the fibers, and to be under increased stress levels when the velocity of external forces increased. From these results, we confirmed that the spinal cord has velocity dependence and anisotropy. The Institutional Animal Care and Use Committee of Yamaguchi University waived the requirement for ethical approval.

Key words: anisotropy dependence, external force, mechanistic analysis, spinal cord injury, straining rate, stress, velocity dependence, white matter

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