Purpose: The integration of living cells into artificial microdevices requires close control of the interfacial interactions. Functional polymer coatings, such as peptide-polymer monolayers, can be used to guide the specific adhesion of living cells on surfaces in a spatially controlled fashion.
Methods: Silicon surfaces were modified with a protein repellent polymer film composed of poly(dimethylacrylamide) (PDMAA) attached to the peptide cell-recognition motif GRGDSP and a subsequent PDMAA backfill. Microstructuring was achieved through a photolithographical process using surface-bound photoreactive benzophenone. Cell adhesion assays with human fibroblasts were conducted to study the capabilities of this approach to induce a directed outgrowth of living cells and to confine cell colony sizes to single cell arrays.
Results: Human fibroblasts follow the chemically imprinted microstructures on peptide-polymer coated substrates. Lines of GRGDSP-PDMAA with a width of 10 µm induce a highly elongated cell shape whereas round spots with a diameter of 50 µm support only single cells per spot. Starting at a center-to-center distance of 100 µm between single peptide-polymer spots, cells are able to "bridge" non-adhesive PDMAA areas.
Conclusions: Peptide-polymer monolayers can direct the outgrowth and restrict the cell colony size through a variation of the imprinted chemical microstructures.