Cell adhesion on supported lipid bilayers functionalized with RGD peptides monitored by using a quartz crystal microbalance with dissipation.

Supported lipid bilayer (SLB) is one of the most widely used structures to mimic cell membranes. To study the cell-cell, cell-matrix and cell-material interactions, supported lipid bilayers (SLBs) functionalized with RGD peptides (SLBs-RGD) were prepared by vesicle fusion on a SiO2 quartz crystal, and subsequently bone mesenchymal stem cells (BMSCs) adhesion was analyzed. A quartz crystal microbalance with dissipation (QCM-D) was utilized to detect the dynamic adsorption behavior of lipid vesicles and BMSCs in real time. Observations obtained by QCM-D signals are confirmed by conducting fluorescence microscopy. QCM-D measurements showed the SLB formation starts at the critical concentration of the vesicles. More BMSCs adhered on SLBs-RGD than on SLBs. With the presence of SLBs, the adhesion cells on SLBs surfaces had a rounded morphology, and cells on SLBs-RGD will take long time to rearrange their cytoskeleton, which led to incomplete spreading compared with SiO2. Differences in adhesion density and adhesion properties of the cells on the different substrates could be traced at the dissipation versus frequency (ΔD/Δf) plots. These results indicate that RGD in/on SLBs could provide anchorage sites for more cells adhesion. QCM-D is demonstrated to be a useful tool for evaluating the interactions between various biological and non-biological systems in situ and in real-time.