Asymmetric peptide nanoarray surfaces for studies of single cell polarization

We report the production of symmetric and asymmetric cell adhesive peptide nanoarrays for the study of single cell polarization. Dip pen nanolithography is used to pattern nanometer-sized spots of hydroquinone terminated alkanethiol on gold substrates. After electrochemical activation of the surface, the corresponding quinone can then undergo a reversible chemoselective reaction with an oxyamine terminated ligand. Substrates presenting both symmetric and asymmetric nanoarrays of immobilized linear Arg-Gly-Asp (RGD) peptides and cyclic (RGD) peptides are used to examine the effect of the spatial distribution of cell adhesive ligands on the polarization of adhered Swiss Albino 3T3 fibroblasts by determining the directional vector between the nucleus centroid, centrosome centroid, and Golgi center. This methodology is extended to investigate the effect of spatial arrangement of immobilized ligands, affinity of ligands, and nanospot size on polarity and focal adhesion formation within the adherent cells on the symmetric and asymmetric nanoarrays.