Development of an impedance based biosensor for studies of spheroids formation

Three-dimensional (3D) multicellular spheroids are exceptional in vitro cell models for their ability to accurately mimic real cell-cell interaction processes. However, the challenges in producing well-defined spheroids with controlled size together with the deficiency of techniques to monitor them significantly restrict their use. Herein, a novel device to study spheroid formation in real time is presented. By exploiting electrochemical impedance spectroscopy, a multi-electrode array (MEA) attached to a calcium alginate scaffold is able to monitor the behaviour of 36 different hydrogel wells. The scaffold contains inverted shape pyramidal microwells, which guide the aggregation of cells into spheroids with controlled dimensions. Preliminar studies on calcium alginate, optimisation of fabrication strategy are shown, together with testing of the device in the presence and the absence of the hydrogel. Lastly, the device was tested for its intended aim, i.e. to monitor the formation of a spheroid, proving its potential as an impedance biosensor.