A multidisciplinary approach based on experiments and mathematical modeling
was used in biomimetic system development for three-dimensional (3D)
cultures of cancer cells. Specifically, two cancer cell lines, human
embryonic teratocarcinoma NT2/D1 and rat glioma C6, were immobilized in
alginate microbeads and microfibers, respectively, and cultured under static
and flow conditions in perfusion bioreactors, while chemical engineering
methods were applied to explain the obtained results. The superficial medium
velocity of 80 mm s-1 induced lower viability of NT2/D1 cells in superficial
microbead zones implying adverse effects of fluid shear stresses estimated
as ~67 mPa. On the contrary, similar velocity (100 mm s-1) enhanced
proliferation of C6 glioma cells within microfibers as compared to static
controls. An additional study of silver release from nanocomposite
Ag/honey/alginate microfibers under perfusion indicated that medium
partially flows through the hydrogel (interstitial velocity of ~10 nm s-1).
Thus, a diffusion-advection-reaction model was applied to describe the mass
transport to immobilized cells within microfibers. Substances with diffusion
coefficients of ?10-9-10-11 m2 s-1 are sufficiently supplied by diffusion
only, while those with significantly lower diffusivities (?10-19 m2 s-1)
require additional convective transport. The present study demonstrates the
selection and contribution of chemical engineering methods in tumor model
system development.