Microscale frictional response of bovine articular cartilage from atomic force microscopy
Microscale frictional response of bovine articular cartilage from atomic force microscopy
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DOI：
10.1016/j.jbiomech.2004.02.017
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发表时间：
2004-11-01
影响因子：
2.4
通讯作者：
Ateshian, GA
中科院分区：
文献类型：
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作者：
Park, S;Costa, KD;Ateshian, GA
本研究的目的是比较牛关节软骨的微观和宏观摩擦系数。使用标准原子力显微镜 (AFM) 技术和 5 pm 球形探针尖端进行微尺度测量。从 6 个新鲜牛肱骨头（4-6 个月大）的相邻位置成对采集 24 个圆柱形骨软骨栓，并将其分为两组进行 AFM 和宏观摩擦测量。观察到摩擦力的 AFM 测量与时间无关，而宏观测量则证明了从最小值到平衡值的时间依赖性增加。微观尺度AFM摩擦系数（mu（AFM），0.152 +/- 0.079）和宏观尺度平衡摩擦系数（mu，0.138 +/- 0.036）没有表现出统计差异（p = 0.50），而宏观最小摩擦系数0.004 +/- 0.001）显着小于mu（eq）和mu（AFM）（p < 0.0001）。关节表面粗糙度的变化 (R-q = 462 +/- 216 nm) 与 mu(AFM)、mu(eq) 或 mu(min) 没有显着相关性。使用赫兹接触分析通过 AFM 压痕测试确定的有效压缩模量为 E* = 45.8 +/- 18.8 kPa。本研究的主要发现是mu(AFM)更能代表宏观平衡摩擦系数，它代表了在没有软骨间质液加压的情况下的摩擦响应。这些结果表明，AFM 测量可能非常适合探索边界润滑剂在关节润滑中的作用，独立于流体加压的混杂效应，以更深入地了解关节软骨润滑。 (C) 2004 Elsevier Ltd. 保留所有权利。
The objective of this study was to compare micro- and macroscale friction coefficients of bovine articular cartilage. Microscale measurements were performed using standard atomic force microscopy (AFM) techniques, using a 5 pm spherical probe tip. Twenty-four cylindrical osteochondral plugs were harvested in pairs from adjacent positions in six fresh bovine humeral heads (4-6 months old), and divided into two groups for AFM and macroscopic friction measurements. AFM measurements of friction were observed to be time-independent, whereas macroscale measurements demonstrated the well-documented time-dependent increase from a minimum to an equilibrium value. The microscale AFM friction coefficient (mu(AFM), 0.152 +/- 0.079) and macroscale equilibrium friction coefficient (mu, 0.138 +/- 0.036) exhibited no statistical differences (p = 0.50), while the macroscale minimum friction coefficient 0.004 +/- 0.001) was significantly smaller than mu(eq) and mu(AFM) (p < 0.0001). Variations in articular surface roughness (R-q = 462 +/- 216 nm) did not correlate significantly with mu(AFM), mu(eq) or mu(min). The effective compressive modulus determined from AFM indentation tests using a Hertz contact analysis was E* = 45.8 +/- 18.8 kPa. The main finding of this study is that mu(AFM) is more representative of the macroscale equilibrium friction coefficient, which represents the frictional response in the absence of cartilage interstitial fluid pressurization. These results suggest that AFM measurements may be highly suited for exploring the role of boundary lubricants in diarthrodial joint lubrication independently of the confounding effect of fluid pressurization to provide greater insight into articular cartilage lubrication. (C) 2004 Elsevier Ltd. All rights reserved.