Modelling and measurement of the O2-concentration for the ex vivo cultivation of cells and tissues

Ex vivo cell and tissue cultures are very important for many scientific and industrial areas. For a broad and efficient use, engineering procedures are necessary to control growth, spread and differentiation of the cultured cells with high accuracy and reproducibility. Ex vivo cell and tissue cultures are accomplished under special, often nonphysiological conditions. A critical parameter is the type of oxygen supply and the estimation of provided O2-quantity per cell and time unit during the ex vivo cultivation. Oxygen is not only a basic prerequisite for all aerobic organisms, but it plays also an essential role as a signal and control element in ex vivo cell and tissue cultures for almost all cellular processes and physiologic responses. The ability of cells to detect the O2-content and its changes in the culture medium and to react differently to it is strongly pronounced and is vital for the survival and proper formation of the cells and tissues. Therefore, for improved and reproducible implementation of the ex vivo cell and tissue cultures using perfusion bioreactors, it is necessary to fulfill a differentiated and fine-controlled management of the O2-supply. And that requires a good modelling of the O2-distribution in the cell cultures as well as a continuous and accurate measuring of the O2-concentration in the culture medium over the time.