The University of Chicago   The Mrksich Laboratory


Model Substrates

We have used self-assembled monolayers as a class of model substrates that present defined ligands on an otherwise non-interacting background and that offer control over the ligand-receptor interactions between a cell and the substrate.37, 49, 68 An important aspect of these surfaces is that monolayers terminated in the tri(ethylene glycol) group are highly effective at preventing the non-specific adsorption of protein and therefore offer a platform for installing ligands that selectively interact with cell-surface receptors. We showed that monolayers presenting the RGD peptide were effective for supporting 3T3 Swiss fibroblast adhesion, migration and growth and that these surfaces were compatible with the routine practices in cell biology; importantly, the thin gold films are transparent and compatible with transmission and fluorescence microscopy. This work has also served to validate the model substrates for experiments involving attached cell culture.

SAM
Figure 1. (Left) Structure of a monolayer that presents the peptide Arg-Gly-Asp mixed with tri(ethylene glycol) groups. (Top right) An optical micrograph that shows 3T3 fibroblasts attached to a monolayer wherein 0.5% of the alkanethiolates present the peptide ligand. (Bottom right) A fluorescent micrograph of a cell that was adherent on these monolayers for 12 hours, fixed and stained with phalloidin-rhodamine. The cells assembled stress fibers that were indistinguishable from those found in cells adherent on fibronectin.