Cell adhesion studies using electrochemical sensors

DIEGO PALLAROLA

La Plata

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Biofísica; 2018

Sociedad Argentina de Biofísica

Cell-cell and cell-extracellular matrix recognition and adhesion are central processes of the cell?s sensory machinery and are mediated by transmembrane adhesion receptors of the integrin family. These processes play a crucial role in most fundamental cellular events including motility, proliferation, differentiation, and apoptosis.The creation of new types of sensitive conductive surfaces capable of mimicking the nanoscale order of the extracellular matrix and with the ability to detect and transduce cell adhesion in real time is of great interest in the field of biomedical research. Electrical-impedance-based sensors are a powerful tool to investigate how cells interact with their environment. These devices are based on impedance measurements using weak and non-invasive AC signals and provide a quantitative description of the cell adhesion process through monitoring changes in the impedance signal in a label-free, instantaneous and non-destructive manner. Our approach was based on the controlled positioning of binding sites for cells through a quasi-hexagonal arrangement of gold nanoparticles deposited on an indium tin oxide microelectrode. The resulting sensors exhibit an ordered pattern of particles that provides not only a precise spatial distribution of adhesive ligands, but an adequate transduction of surface events into electrical signals. The use of transparent electrodes allows for simultaneous and real-time monitoring of cell adhesion using electrochemical and optical microscopy techniques. Particularly, these sensors were applied to study cell-cell and cell-substrate interactions of epithelial cells on surfaces coated with cyclic pentapeptide ligands with different binding affinities to integrins αvβ3 and α5β1.