  An adequate control of cell response in tissue engineering applications is of
utmost importance to obtain products suitable to clinical practice. This paper
is the first part of a series of two connected publications in which we study
via mathematical tools the cultivation in bioreactors of articular
chondrocytes. The proposed model combines poroelastic theory of mixtures and
cellular population models into a framework including stress state and oxygen
tension as main determinants of engineered culture evolution. The special
mechanosensitivity of articular chondrocytes to the surrounding environment is
accounted for in the model through the novel concept of "force isotropy" acting
on the cell which is assumed as the promoting factor of the production of new
cells or extracellular matrix.
