The study on the mechanical characteristics of articular cartilage in simulated microgravity
The study on the mechanical characteristics of articular cartilage in simulated microgravity
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模拟微重力下关节软骨的力学特性研究
DOI：
10.1007/s10409-012-0150-3
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发表时间：
2012-10-01
影响因子：
3.5
通讯作者：
Fan, Yu-Bo
中科院分区：
文献类型：
--
作者：
Niu, Hai-Jun;Wang, Qing;Fan, Yu-Bo
长期空间飞行的微重力环境可能引起宇航员肌肉骨骼系统的剧烈变化。本研究探讨模拟微重力对关节软骨力学特性的影响。6只大鼠进行尾部悬吊14天，另外6只大鼠保持在正常地球重力下作为对照。使用高频超声测量所有受渗透负荷的软骨样品中的肿胀应变。在软骨膨胀的三相理论模型中使用特定位点的膨胀应变数据来确定软骨固体基质的单轴模量。在从对照组或尾部悬吊组获得的软骨样品中未发现严重的表面不规则性。对于尾部悬吊组，通过超声回声确定的指定部位的软骨厚度显示出轻微的减少。特定部位关节软骨的单轴模量显著降低，从（6.31 ± 3.37）MPa降至（5.05 ± 2.98）MPa（p < 0.05）。软骨样本的组织学染色图像也显示软骨细胞数量减少和基质染色程度降低。这些结果表明，14 d模拟微重力对关节软骨的力学特性产生了显著的影响。本研究首次尝试采用渗透压加载方法和三相模型探讨模拟微重力对关节软骨力学特性的影响。这些结论可为载人航天飞行提供参考信息，并为更好地了解微重力对骨骼系统的影响提供参考。
The microgravity environment of a long-term space flight may induce acute changes in an astronaut's musculo-skeletal systems. This study explores the effects of simulated microgravity on the mechanical characteristics of articular cartilage. Six rats underwent tail suspension for 14 days and six additional rats were kept under normal earth gravity as controls. Swelling strains were measured using high-frequency ultrasound in all cartilage samples subject to osmotic loading. Site-specific swelling strain data were used in a triphasic theoretical model of cartilage swelling to determine the uniaxial modulus of the cartilage solid matrix. No severe surface irregularities were found in the cartilage samples obtained from the control or tail-suspended groups. For the tail-suspended group, the thickness of the cartilage at a specified site, as determined by ultrasound echo, showed a minor decrease. The uniaxial modulus of articular cartilage at the specified site decreased significantly, from (6.31 +/- 3.37)MPa to (5.05 +/- 2.98)MPa (p < 0.05). The histology-stained image of a cartilage sample also showed a reduced number of chondrocytes and decreased degree of matrix staining. These results demonstrated that the 14 d simulated microgravity induced significant effects on the mechanical characteristics of articular cartilage. This study is the first attempt to explore the effects of simulated microgravity on the mechanical characteristics of articular cartilage using an osmotic loading method and a triphasic model. The conclusions may provide reference information for manned space flights and a better understanding of the effects of microgravity on the skeletal system.