Effects of Cyclic Loading and Binding to Extracellular Matrix on Macromolecular Transport in Soft Biological Tissue - Progress in Organic and Physical Chemistry: Structures and Mechanisms - page 101

FIGURE 12 The average gains of free, bound, and total solute as a function of frequency.
Note, that for higher frequency the time point of calculation is lower (times are shown in boxes
under data). The average gain for the case of the solute that does not bind to matrix is shown
by triangles.
7.5.2 Comparison with Experimental Data
Few experimental data on molecular transport in gels under cyclic loading is avail-
able to date, even for non-binding solutes. Experiments are performed mainly on
cylindrical cartilage explants, subjected to high deformation amplitudes [3, 5, 7].
Desorption or absorption rates have been measured for solutes of different sizes.
Their dependence on frequency and strain has been described. But it is question-
able to use the experimental results for high strains (10-50%) to compare with the
model predictions, because we use the assumption of small strains while deriving
the equations.
To demonstrate the correlation of our model with experimental results, we have
compared the theoretical predictions with the data obtained by Quinn et al. (2002)
[4]. The authors investigated the radial desorption of 3kDa dextran from cylindrical
cartilage explant under 0.001Hz, 5% dynamic loading. Using À uorescence, they have
obtained the concentration pro¿ le of dextran as a function of radial distance from the
lateral surface at 1 hr after the beginning of desorption from initial homogeneous state.
Radius of cartilage disk was 1.5 mm. The corresponding concentration pro¿ le for dif-
fusion without loading has also been obtained.