• Bioreactors
• In-vitro models
• Physiological Barriers
• TEER

Physiological barrier have a fundamental role in human homeostasis, as they are the main gate for the passage of chemical compounds, as well as the first defence against toxic agents. For this reason, predictive in-vitro models of these barriers are very important to study drug and toxicants absorption, monitoring the integrity of the cell layer as an index for toxic or healthy effect. An established parameter to quantify the status of cell monolayer is the Trans Epithelial Electric Resistance (TEER), which evaluates the formation of tight junctions in endothelial and epithelial barriers. Classical in-vitro models are based on cells cultured on permeable supports in static conditions and TEER measurements are performed with a chopstick electrode. However, since dynamic models are nowadays affirming as the better way to mimic physiological conditions, the integration of TEER measurement systems in these devices is the new challenge.
In this work, silver electrode and a measuring system have been integrated in a bioreactor to perform standalone TEER measurement and monitor the monolayer integrity during time. The system was tested with Human Umbilical Vein Endothelial Cells (HUVECs) and Brain endothelial cells (bEnd3), evaluating TEER and cell viability in dynamic conditions for up to 5 days.