Fabrication of arrays of polymer gradients using inkjet printing.

Arrays of 84 polymer gradients, fabricated on a single glass microscope slide, were generated by inkjet printing, allowing a combination of high-throughput and true combinatorial methods. The gradual change of composition within the polymer gradients, consisting of two different monomers and a cross-linker, was validated by XPS and fluorescence analysis. Cellular screening of the gradients allowed the rapid identification of optimal polymer compositions for binding of the suspension cell line K562 and the adherent cell line HeLa. The polymers identified were identical to those identified by previous microarray data, providing proof of concept for the successful application of the polymer gradient arrays as a screening tool. In addition, the polymer gradients could be readily modified by conjugation enabling the generation of bio-molecule gradients.