Role of fiber functionality and angle on cell migration.

In order to determine the role of surface interactions on cell migration we compared the cell velocity on electrospun PMMA fibers which were either etched with UV/ozone plasma, had pre-adsorbed Fibronectin or both. It shows that dermal fibroblasts (CF-29, ATCC) did not adhere to the fibers without treatment, and the migration of cells was fastest on with both etching and pre-coat FN fibers. Vinculin was used to stain for the focal adhesion points and the largest number per cell were found on the FN pre-incubated samples, and nearly none on the plasma etched surface, despite good proliferation and migration. The results indicate that the migration velocity need not directly correlate to the cell adhesion. Using FN coated fibers we also studied the effect of angle on crossed fibers. We found that there was a clear preference by the cells for crossing a matrix where the fibers were oriented at 30 degrees. At this angle the migration velocity was slowest. Movies of the migrating cells indicate that the residence time of the cells at junctions with this angle is the longest cut to the interactions of the motion between fibers. The largest speed was observed for fibers placed at 90 degree.