Kinetics of oxygen uptake by cells potentially used in a tissue engineered trachea

Synthetic polymer scaffold seeded with autologous cells have a clinical translational potential. A rational design oriented to clinical applications must ensure an efficient mass transfer of nutrients as a function of specific metabolic rates, especially for precariously vascularized tissues grown in vitro or integrated in vivo. In this work, luminescence lifetime-based sensors were used to provide accurate, extensive and non-invasive measurements of the oxygen uptake rate for human mesenchymal stem cells (hMSCs), tracheal epithelial cells (hTEpiCs) and human chondrocytes (hCCs) within a range of 2-40% O2 partial pressure. Estimated Michaelis-Menten parameters were: Vmax = 0.099 pmol/cell⋅h and KM = 2.12 × 10−7 mol/cm3 for hMSCs, Vmax = 1.23 pmol/cell⋅h and KM = 2.14 × 10−7 mol/cm3 for hTEpiCs, Vmax = 0.515 pmol/cell⋅h and KM = 1.65 × 10−7 mol/cm3 for hCCs. Kinetics data served as an input to a preliminary computational simulation of cell culture on a poly-ethylene terephthalate (PET) tracheal scaffold obtaining an efficient mass transfer at cell density of 106 cell/cm3. Oxygen concentration affected the glucose uptake and lactate production rates of cells that adapted their metabolism according to energy demand in hypoxic and normoxic conditions.