Monitoring of monolayer and multilayer growth for epithelial sheet formation

The profiles of monolayer and multilayer growth of epithelial cells were kinetically analyzed based on the rates of cell proliferation and glucose consumption. The cells were classified into two populations in proliferative and non-proliferative states, and in the monolayer growth most of the cells were regarded as being proliferative. In the multilayer growth, the proliferative cells decreased with elapsed time, causing an increase in the non-proliferative cells. The kinetic analysis indicated that the proliferative cells consumed glucose for cell mass production (anabolism) and metabolic maintenance (catabolism), while the non-proliferative cells utilized glucose exclusively for the latter. Employing the kinetic equations with the determined parameters, the population balance of proliferative and non-proliferative cells could be estimated throughout the monolayer and the multilayer growth periods. The bioreactor system which permits to determine glucose concentration automatically was constructed, and the monitoring in the culture of epithelial cells was performed in a non-invasive manner by considering glucose consumption of the two populations in the epithelial sheets. It was found that the kinetic analysis was valid for monitoring the growth profiles of cells in the bioreactor, giving fair agreement between calculated and experimental values.