Nature Methods 12, 134–136 (2015)

Credit: NATURE PUBLISHING GROUP

The behaviour and organization of cells can be regulated by appropriate cues on cell-culture substrates. For example, neural cells have been aligned by depositing them on flat substrates coated with gradients of cell-adhesive molecules, and tissues can be grown asymmetrically on substrates by patterning (typically, with soft lithography) appropriate combinations of physical and chemical patterns. However, independent control of topography and chemistry on structured (rough) substrates has been difficult to achieve. Now, Adam Feinberg and colleagues report a method for the transfer of defined patterns of proteins to topographically complex surfaces. First, a topographically patterned substrate is brought into contact with glass coverslips spin-coated with a thermally sensitive polymer and patterned (through microcontact printing) with a protein, and then the system is cooled down. As the polymer swells and dissolves on reaching its lower critical solution temperature, hydrophobic interactions force the protein to form a conformal ∼5-nm-thick layer on the patterned surface. The researchers used the method to characterize the responses of cardiac cells to orthogonal topographic and chemical cues.