Chondrocyte metabolism and matrix nano-electromechanics : the response to cartilage tissue shear deformation

Cartilage functions as a load bearing and friction reducing material in synovial joints and it is constantly exposed to in vivo loading which is coupled to electromechanical and physicochemical forces. The swelling pressure of cartilage originates from proteoglycans containing negatively charged carboxyl and sulfate groups within glycosaminoglycans. Proteoglycans are embedded within the network of collagen fibrils whose molecular structure (supercoiled helix of three alpha-chain subunits) provides resistance to tensile forces, and contributes to the overall poroviscoelastic behavior of the tissue. The dynamic balance between repulsive and tensile forces gives cartilage unique compressive and shear stiffness that varies with the rate of deformation. Chondrocytes synthesize and degrade matrix components influenced by the regulatory signals present in the extracellular matrix. The transduction mechanisms by which mechanical signals are converted to a biological response are not completely understood. Therefore, the knowledge of both biological and biophysical aspects of cartilage is important to understand the dynamic interaction between the cells and matrix. In this study, the electromechanical properties of cartilage have been studied by measuring equilibrium and dynamic shear stiffness as a function of the ionic concentration of bath solution. Measured shear properties were dependent on ionic concentration; the shear modulus increased and the phase angle between stress and strain decreased with decreasing ionic concentration.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2002

Author dc:creator

• Jin, Moonsoo, 1971-

Advisor dc:contributor.advisor

• Alan J. Grodzinsky.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8328

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8328