Characterization of Extracellular Matrix (ECM) Produced by MC3T3 Cells Using Thickness Shear Mode (TSM) Resonators

Quartz thickness shear mode (TSM) resonators for monitoring the attachment and spreading of mammalian cells have been investigated in the past years. Recent studies have shown that the TSM resonator signal is not only contributed by cellular body closed to the resonator substrate, but also contributed by the extracellular matrix (ECM), which is a protein layer between the cellular body and the resonator surface. Therefore, the quartz TSM resonator is expected to provide a simple, quantitative and effective method to characterize the ECM produced by cells. In this study, we investigate the use of quartz TSM resonators to monitor the ECM production by cells in real time and to characterize the mechanical properties and the thickness of this protein layer. MC3T3-E1 fibroblasts are chosen in our study because they are an established cell line that is stable in culture from passage to passage and they can produce abundant collagenous matrix within a relatively short culture period. AT-cut quartz crystal resonators coated with gold electrodes on both sides are used in this study. An impedance analyzer is used for measuring the admittance spectra and total parallel capacitance of the resonators. Multilayer model is constructed to characterize the mechanical properties and thickness of the ECM layer by using a curve-fitting method. The results obtained by TSM resonator sensors show a good agreement with those obtained by chemical methods