Effect of postmortem changes and freezing on the viscoelastic properties of vocal fold tissues
Effect of postmortem changes and freezing on the viscoelastic properties of vocal fold tissues
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DOI：
10.1114/1.1561287
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发表时间：
2003-04-01
影响因子：
3.8
通讯作者：
Titze, IR
中科院分区：
文献类型：
--
作者：
Chan, RW;Titze, IR
在喉部研究实验室中，通常的做法是将切除的喉部和声带组织标本冷冻储存，大概是为了保持组织的活力和结构完整性。用于生理和生物力学实验的标本。然而，对声带组织死后变化和冷冻保存的生物力学效应知之甚少。本研究试图量化死后变化和冷冻对犬声带粘膜粘弹性剪切特性的影响。在存活状态下，从成年犬死后立即切除16个喉。使用扭转流变仪，通过线性小振幅振荡实验测量来自每个喉的一个声带的粘膜组织的复合剪切模量（G*）作为频率（0.01-15 Hz）的函数。在室温下死后在盐水溶液中储存24小时后，对10份粘膜标本重复测量。将16个喉中的11个冷冻并储存在-20 ℃下，其中6个以慢速冷却（储存在普通冰箱中），另外5个通过快速冷冻（冷冻储存前用液氮冷却）。一个月后缓慢解冻喉过夜，测量对侧声带粘膜的粘弹性剪切特性。结果表明，声带粘膜的弹性剪切模量（G '）和动态粘度（η'）在室温下在生理盐水中保存24 μ l后，以及在快速冷冻后冷冻保存一个月后，似乎没有显著变化，而对于缓慢冷冻的组织，G'和η'均显著降低。这些发现支持了使用快速冷冻保存喉组织用于体外生物力学测试、切除喉实验和组织工程应用的可行性。(C)2003生物医学工程学会。
It is common practice in laryngeal research laboratories to store excised larynges and vocal fold tissue specimens frozen, presumably to preserve viability and structural integrity of the. specimens for physiologic and biomechanical experiments. However, little, is known about the biomechanical effects of postmortem changes and frozen storage in vocal fold tissues. This study attempted to quantify the effects of postmortem changes and freezing on the viscoelastic shear properties of the canine vocal fold mucosa. Sixteen larynges were excised from adult dogs immediately postmortem in a viable state. Using a torsional rheometer, the complex shear modulus (G*) of the mucosal tissue from one vocal fold of each larynx was measured as a function of frequency (0.01-15 Hz) by linear small-amplitude oscillation experiments. Measurement was repeated for ten mucosal specimens after 24 It of postmortem storage in saline solution at room temperature. Eleven of the 16 larynges were frozen and stored at -20degreesC, six of them at a slow rate of cooling (storage in a regular freezer) and five others by quick freezing (chilling by liquid nitrogen prior to frozen storage). The larynges were thawed slowly overnight after one month and the viscoelastic shear properties of the contralateral vocal fold mucosa were measured. Results showed that the elastic shear modulus (G') and dynamic viscosity (eta') of the vocal fold mucosa did not seem to change significantly after 24 It of storage in saline at room temperature, nor after one month of frozen storage following quick freezing, whereas both G' and eta' decreased significantly for tissues that were slowly frozen. These findings supported the feasibility of using quick freezing to preserve laryngeal tissues for in vitro biomechanical testing, for excised larynx experiments, and for tissue engineering applications. (C) 2003 Biomedical Engineering Society.