Controlled macrophage adhesion on micropatterned hydrogel surfaces

We studied the protein adsorption and subsequent macrophage adhesion on polyethylene glycol) [PEG] hydrogels crosslinked using a focused electron beam. Thin-film gels were patterned on silicon substrates and could be formed with swell ratios (hydrated height/ dry height) anywhere between fifteen and unity. We have shown that laminin does not adsorb onto highly swelling gels but that it does adsorb on heavily-crosslinked low-swelling gels. As part of ongoing research on patterning surfaces to control neurite growth in the context of the inflammatory environment of a spinal cord injury, we are interested in how these gel surfaces interact with macrophages. We show that the high-swelling PEG gels resist macrophage adhesion, but the macrophages adhere to low-swelling gels pre-exposed to laminin. By spatially patterning combinations of low and high swelling gels, we show that macrophage adhesion can be confined to specific locations on a surface.