The Ismagilov and Mrksich groups at the University of Chicago MRSEC have recently established that a microfluidic system utilized in conjunction with surface immobilization chemistries can be used to pattern surfaces with well-defined gradients of adhesion molecules for the attachment of cells. The images show the patterned surfaces after placement in a suspension of B16F10 mouse melanoma cells and fixing and immunostaining with antibody against vinculin (found in the focal adhesion structures integrating the cytoskeleton with the extracellular matrix). Each gradient microisland contained a nonuniform distribution of active ligands for cell adhesion.
The general technique of preparing gradients of immobilized species with specific patterns is expected to be an important tool for understanding the influence of nonuniform microenvironments on cell function, including polarization and migration.
