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Aggrecan: Approaches to Study Biophysical and Biomechanical Properties

  • Hadi Tavakoli Nia
  • Christine Ortiz
  • Alan GrodzinskyEmail author
Protocol
Part of the Methods in Molecular Biology book series (MIMB, volume 1229)

Abstract

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.

Key words

Aggrecan Atomic force microscopy Nanomechanics Biophysics Ultrastructure Cartilage Extracellular matrix Dynamic modulus Elasticity Poroelasticity Viscoelasticity 

Notes

Acknowledgements

Supported by Whitaker Foundation Fellowship, National Science Foundation (grant CMMI-0758651), and National Institutes of Health (grant AR060331).

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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Hadi Tavakoli Nia
    • 1
  • Christine Ortiz
    • 2
  • Alan Grodzinsky
    • 3
    Email author
  1. 1.Department of Mechanical EngineeringMITCambridgeUSA
  2. 2.Department of Materials Science and EngineeringMITCambridgeUSA
  3. 3.Department of Biological Engineering, Electrical Engineering and Computer Science, and Mechanical EngineeringMITCambridgeUSA

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