Extracellular matrix remodelling during cell adhesion monitored by the quartz crystal microbalance

A cell's ability to remodel adsorbed protein layers on surfaces is influenced by the nature of the protein layer itself. Remodelling is often required to accomplish cellular adhesion and extracellular matrix formation which forms the basis for cell spreading, increased adhesion and expression of different phenotypes. The adhesion of NIH3T3 (EGFP) fibroblasts to serum protein (albumin or fibronectin) precoated tantalum (Ta) and oxidised polystyrene (PSox) surfaces was examined using the quartz crystal microbalance with dissipation (QCM-D) monitoring and fluorescence microscopy. The cells were either untreated or treated with cycloheximide to examine the contribution of endogenous protein production during cell adhesion to the QCM-D response over a period of 2 h. Following adsorption of albumin onto Ta and PSox there was no difference detected between the response to seeding untreated and cycloheximide treated cells. The QCM-D was able to detect differences in the untreated cellular responses to fibronectin versus serum precoated Ta and PSox substrates, while cycloheximide treatment of the cells produced the same QCM-D response for fibronectin and serum precoatings on each of the materials. This confirmed that the process of matrix remodelling by the cells is dependent on the underlying substrate and the preadsorbed proteins and that the QCM-D response is dominated by changes in the underlying protein layer. Changes in dissipation correspond to the development of the actin cytoskeleton as visualised by actin staining.