This paper characterizes the mass transfer and replenishment of glucose and oxygen in tissue engineered cartilage constructs by a numerical approach. Cell population growth modulated by glucose and oxygen is incorporated in the mathematic model. The distribution of synthesized type II collagen and its influence on mediating the chondrocyte growth over scaffold are also investigated. Results from simulation are compared with the experiments in literature to verify the formulation and predictions. It is found that, under static culture, the oftentimes observed phenomenon that the overall cell number densities in thick scaffolds are smaller than in thin scaffolds is mainly due to depletion of glucose rather than oxygen. Cell growth is found to be more sensitive to the change in glucose concentration for thick scaffolds, whereas to be more sensitive to the change in oxygen concentration for thin scaffolds. Results also demonstrate the modulation of chondrocyte growth by type II collagen, presenting the biphasic impact of type II collagen which promotes chondrocyte growth in the initial phase of cultivation, while inhibits cell growth in the long term. The numerical model provides a useful reference for developing cartilaginous constructs in tissue engineering.
