Cells and Materials


Fibronectin, a major attachment protein, has been thought to be involved in pathway guidance, a process in which cells migrate along specific pathways within a tissue during development. Fibroblasts exhibit the phenomenon of contact guidance, the tendency of cells to be guided in their direction of migration by the shape of the substratum. The purpose of our study was to test the hypothesis that fibronectin tracks are deposited by fibroblasts moving on smooth and grooved titanium surfaces.

The study was carried out on human gingival fibroblasts which were plated onto both smooth and grooved titanium substrata using medium containing either serum or fibronectin-depleted serum. The migratory paths of the cells were determined by time-lapse photography using reflected-light differential-interference- contrast optics. Anti-fibronectin antibody, 1 nm gold particle conjugated secondary antibody, and silver enhancement techniques were applied to the cultured cells, and the specimens observed in a scanning electron microscope using backscattered detection. By correlating the paths of the cells with the location of the fibronectin- containing material, it could be demonstrated that cells left behind fibronectin tracks on both smooth and grooved titanium surfaces. Fibronectin tracks appeared to be deposited more abundantly by fibroblasts cultured in medium with 5 % serum depleted in fibronectin than in complete, i.e., non-depleted, 5 % serum. On the grooved titanium substratum, the tracks were found on the ridges as well as on the floors and walls of the grooves. The fibronectin tracks are aligned with the grooves so that they would be expected to reinforce the contact guidance produced by the substratum.