Content area

Abstract

Equilibrium and transient swelling of connective tissues is examined in unconstrained conditions and in an isometric tension test. The unconstrained experiment shows that cartilage contacts with increasing NaCl concentration in a linear manner for small concentration differences. The linear proportionality constant is termed the coefficient of chemical contraction. The magnitude of this dimensional change is a function of the collagen fibrillar array and proteoglycan content and structure of tissue samples. Equilibrium results of the isometric tension test demonstrate that the tensile modulus of cartilage decreases with increasing salt concentration. Non-equilibrium results shed light on the kinetic processes involved in swelling and contraction. When subjected to a sudden rise of NaCl concentration, cartilage in isometric tension responds in a manner dependent on both the free contraction and the decrease of modulus. The tensile force trace is bimodal at low applied strains and monotonic at high strains. Also, the force trace is characterized by a single time constant at high applied strain but not at low ones.

An adaptation of the linear biphasic theory for cartilage is made to model this response. Results from the model indicate that the time course of the isometric force at low strains is a function of the ratio of two time constants; the gel diffusion time and the salt diffusion time. However, at high strains, the transient effects of salt diffusion alone seem to dominate the time course. Magnitudes of the force changes depend on material properties including the coefficient of chemical contraction. The parameters from the model together with the experimental results seem to reflect tissue structure and content. This hypothesis is tested by measuring the isometric response in several connective tissues and in biochemically altered samples of cartilage.

Details

Title
KINETIC AND EQUILIBRIUM SWELLING STUDIES OF CONNECTIVE TISSUES
Author
MYERS, ELIZABETH READ
Year
1984
Publisher
ProQuest Dissertations & Theses
ISBN
979-8-204-41828-8
Source type
Dissertation or Thesis
Language of publication
English
ProQuest document ID
303318182
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.