Real-time analysis of hepatocyte growth factor induced cell motility with quartz crystal resonators

Kinetics of hepatocyte growth factor (HGF) induced changes in adhesion strength of Madin-Darby canine kidney (MDCK-II) cells on a quartz crystal resonator (QCR) have been analyzed. First, MDCK-II cells were cultivated on the gold electrode of a QCR in a micro fluidic bioreactor. Second, adherent cells were stimulated with hepatocyte growth factor (HGF) in culture medium. Cell cultivation as well as stimulation was done in flow-through and overpressure regime. The QCR response was monitored online with an impedance analyzer. Furthermore, online light microscopy was applied for optical analysis of cell motility and the grade of confluence. Light microscope pictures showed that cell motility in the bioreactor was less prominent compared to experiments in conventional cell culture. First results suggest that HGF induces an alteration in acoustic shear wave propagation. The acoustic load, respectively stiffness and density, of the cell-sensor interface, changed significantly even when optically no cell motility could be observed.