Cell guidance by micropatterned adhesiveness in vitro

Tracks of adhesiveness are believed to be involved in guiding morphogenetic cell migrations. Here, electronics microfabrication technology was used to manufacture patterns of alternating tracks of adhesive and non-adhesive substratum (untreated fused quartz and adjacent parallel tracks of hydrophobic treatment) of varying period (4, 6, 12, 24 and 50 microns). These experimental substrata were used to model, in vitro, possible differentially adhesive guidance cues. The effect of such patterned substrata was assessed using fibroblastic BHK cells and epithelial MDCK cells. Cells were oriented and elongated by these surfaces. Their responsiveness was dependent on cell type, cell-cell interactions, and the geometry of the patterns. Alignment of BHK cells increased with increasing pattern period. Single MDCK cells aligned to all pattern periods, their elongation being period-dependent, whereas colonies were mainly unaffected. These in vitro data have important implications, which are discussed with regard to in vivo guidance cues. The ability of cells to bridge over non-adhesive regions will influence the effectiveness of linear cues, and will be important for guideposting. The geometry of patterns of differential adhesion is here shown to be an important factor in determining the precision with which local guidance of cells may be controlled.