Nia Hadi Tavakoli, Ortiz Christine, Grodzinsky Alan
Department of Mechanical Engineering, MIT, 500 Technology Square, Cambridge, MA, 02139, USA.
Methods Mol Biol. 2015;1229:221-37. doi: 10.1007/978-1-4939-1714-3_20.
Aggrecan, the most abundant extracellular proteoglycan in cartilage (~35 % by dry weight), plays a key role in the biophysical and biomechanical properties of cartilage. Here, we review several approaches based on atomic force microscopy (AFM) to probe the physical, mechanical, and structural properties of aggrecan at the molecular level. These approaches probe the response of aggrecan over a wide time (frequency) scale, ranging from equilibrium to impact dynamic loading. Experimental and theoretical methods are described for the investigation of electrostatic and fluid-solid interactions that are key mechanisms underlying the biomechanical and physicochemical functions of aggrecan. Using AFM-based imaging and nanoindentation, ultrastructural features of aggrecan are related to its mechanical properties, based on aggrecans harvested from human vs. bovine, immature vs. mature, and healthy vs. osteoarthritic cartilage.
聚集蛋白聚糖是软骨中含量最丰富的细胞外蛋白聚糖（约占干重的35%），在软骨的生物物理和生物力学特性中起关键作用。在此，我们综述了几种基于原子力显微镜（AFM）的方法，以在分子水平上探测聚集蛋白聚糖的物理、力学和结构特性。这些方法在从平衡到冲击动态加载的广泛时间（频率）尺度上探测聚集蛋白聚糖的响应。描述了用于研究静电和流固相互作用的实验和理论方法，这些相互作用是聚集蛋白聚糖生物力学和物理化学功能的关键机制。基于从人源与牛源、未成熟与成熟、健康与骨关节炎软骨中获取的聚集蛋白聚糖，利用基于AFM的成像和纳米压痕技术，将聚集蛋白聚糖的超微结构特征与其力学性能相关联。
