Hexagonal micron scale pillars influence epithelial cell adhesion, morphology, proliferation, migration, and...

A desirable attribute of implants penetrating epithelium is the inhibition of downward epithelial migration. Simple grooved topographies can inhibit this migration either directly or indirectly by promoting connective tissue attachment, but few studies have focused on the direct effect of geometrically complex topographies on epithelial behavior. Therefore, we examined the influence of novel topographies comprising square floors surrounded by six-sided pillars on periodontal ligament epithelial cell adhesion, morphology, cytoskeletal organization, and migration. Relative to cells on smooth surface, epithelial cells on the pillar substrata adhered closely, exhibited reduced proliferation, had a reduced velocity, but higher persistence. Vinculin staining demonstrated that cells formed mature adhesions on the pillar tops, but smaller punctate adhesion in the gaps and on the pillar walls. Overall more mature adhesions were found on pillars compared to smooth surfaces, which may account for the reduced speed of migration limited on the pillars. F-actin stress fibers were predominantly found on pillar tops within 6 h, whereas microtubules (MTs) had a tendency to form in the gaps between the six-sided pillars. In conclusion, microfabricated pillars altered epithelial migration in ways that could prove useful in inhibition of epithelial downward migration on transmucosal implants.