Shear Modulus:(Dynamic 05Hz, 0.8% strain 2.5 (B) 0.75 Dynamic G 2 1.5 0.5 Equilibrium G 0.25 0 (C) (Mean±sD,n=4 Dynamic Phase 17.5 0.01 0.1 lonic concentration M Like charge repulsion accounts for a large fraction(50%)of the stiffness in tissues with high GAG content These effects can be eliminated either by shielding (importance of Debye length --BE. 430 )with counter-ions or neutralization by changing pH 士Shear Modulus: (Dynamic @ 0.5Hz, 0.8% strain) Jin+, Macromolecules, 2001 Equilibrium G Dynamic G Dynamic Phase Like charge repulsion accounts for a large fraction (~50%) of the stiffness in tissues with high GAG content. These effects can be eliminated either by shielding (importance of Debye length -- BE.430!) with counter-ions or neutralization by changing pH. + + + + + + + + + + + + + + + + + + + + + + + + + + + + 17