On-line Überwachung von Säugetierzellkulturen zur Gewinnung von physiologischen Informationen in Echtzeit

Abweichender Titel laut Übersetzung der Verfasserin/des VerfassersWithin the last years, more and more attention has been paid to the development of on-line monitoring process devices. Particularly, taking into account that the Food and Drug Administration (FDA) launched the Process Analytical Technology (PAT) guidance, which encouraged biopharmaceutical companies to ensure a pre-defined final product quality. On-line sensors are a great opportunity to gather process understanding and to enhance process development. In course of this thesis the usefulness of on-line and in-line measurements to deduct physiological key parameters and accelerate bioprocess development is evaluated using different human embryonic kidney (HEK) cell clones. On the one hand an on-line photometric measurement system for the quantification of amino acids and carbohydrates was used. In order to make it useable for cell culture systems it was necessary to meet the high sterility requirements and to adopt the technique to a completely different physiological system. To characterise the system the accuracy and precisions was proven in repeated measurements of standard solutions. The robustness was tested by applying the approach on different cell clones. Furthermore, analytical parameters such as the Limit of Detection, the Limit of Quantitation, the linear working range and the precision and accuracy were determined in the run-up using the device in off-line mode. On the other hand an in-line capacitance probe for the calculation of the viable cell count was implemented. To find a suitable calibration for the in-line device a novel approach based on Multiple Linear Regression was used. These two individual measurements were tied together in order to get a full picture of the bioprocess. The on-line data were transferred into rates and yields, which is the scale independent and time resolved form of information. In other words, two on-line monitoring devices were coupled and a novel device was created to gather real-time information of mammalian cell cultures. The high frequent determination of physiological data allows to image the dynamic of the culture precisely. Process events, like accumulations and limitation can be detected in real-time and moreover physiological considerations could be drawn using specific rates and yields, which allowed a deeper insight in the metabolism of different cell clones and enhances the process of strain selection and therefore supports and fastens bioprocess development. Prospectively, this approach may be used not only to detected limitations in-time but furthermore it will provide the basis for intelligent controlling9