Hydrodynamics in Porous Media with Applications to Tissue Engineering - Porous Media: Applications in Biological Systems and Biotechnology - page 105

Variation of the
concentration

Principal axis

Higher
concentration

X'

Lower
concentration

C'

0.969 0.924

FIGURE 3.11
Spatial distribution of the dimensionless oxygen concentration in the vicinity
of two adjacent fiber surfaces where the cells are lying. The mixing effects
owing to the swirling flow with transverse velocity components are contribut-
ing to the homogenization of the oxygen distribution. In this tested part
involving an overall relative variation in oxygen concentration of about 10%
around the mean value is noted.

fibers. These results are significantly different (one or two orders of magnitude
lower) from those obtained with a two-dimensional model, where higher ampli-
tudes and more uniform distribution of shear stresses were found (Pierre and
Oddou 2007). Moreover, they are also significantly different and lower from
those experimentally obtained in in vitro mechanotransduction assays using
parallel-plate flow chambers. Such results can bring additional insight, leading
to a detailed knowledge of the cell mechanotransduction phenomena taking
place in bone tissue engineering. Indeed, as recently shown (Pedersen and
Swartz 2005), they point out “the relevance and importance of dimensionality
in mediating cellular responses to the biophysical environment.”

3.5.3.2 Microfluidic Bioreactor: A Numerical Driven Experiment

for Cartilage Culture

In this section, the behavior of a microfluidic bioreactor is investigated using
a modeling approach. Four different cases corresponding to experimental con-
ditions were defined regarding the tissue thickness (250

m or 1 mm, depend-
ing upon the initial cell seeding conditions) and the intensity of the applied

µ