Micropatterning of proteins and mammalian cells on biomaterials

Controlling the spatial organization of cells is vital in engineering tissues that require precisely defined cellular architectures. For example, functional nerves or blood vessels form only when groups of cells are organized and aligned in very specific geometries. Yet, scaffold designs incorporating spatially defined physical cues such as microscale surface topographies or spatial patterns of extracellular matrix to guide the spatial organization and behavior of cells cultured in vitro remain largely unexplored. Here we demonstrate a new approach for controlling the spatial organization, spreading, and orientation of cells on two micropatterned biomaterials: chitosan and gelatin. Biomaterials with grooves of defined width and depth were fabricated using a two-step soft lithography process. Selective attachment and spreading of cells within the grooves was ensured by covalently modifying the plateau regions with commercially available protein resistant triblock copolymers. Precise spatial control over cell spreading and orientation has been observed when human microvascular endothelial cells are cultured on these patterned biomaterials, suggesting the potential of this technique in creating tissue culture scaffolds with defined chemical and topographical features.