Effect of Surface-Roughness on Epithelial Growth, Spreading, and Focal-Contact Formation

Although there is extensive research on the response of osteoblast cells to rough titanium surfaces, little is known about the interactions of epithelial cells with roughTi surfaces. Objective: To determine the effect of differing degrees of surface roughness of titanium surfaces on the growth, spreading, and focal-contact (FC) formation of epithelial cells (E-cells). Methods: E-cells derived from porcine periodontal ligament were cultured on tissue culture plastic, Thermonox®‚ (TCP), polishedTi (P), grit blastedTi (B), acid etchedTi (AE), and grit blasted and acid etched Ti (SLA) surfaces. Cells were stained with propidium iodide and counted using fluorescence microscopy. Scanning electron microscopy was used to measure the cell area and morphology. Confocal immunofluorescence microscopy was used to examine the presence and distribution of actin and FCs (as assessed by anti-vinculin antibody staining). Statistical analysis employed analysis of variance and Jump-In software. Results: Cell number was measured at days 1, 2, 3, 4 and 5 of culture; significantly (p <. 001) more cells were found on TCP and P surfaces compared to the rougher (B, AE, SLA) surfaces. Moreover, when isolated cells were considered the area/cell was significantly higher (p < .001) on TCP, P, and AE surfaces compared to B and SLA surfaces. When cell clusters were measured, area/cell was significantly (p < .001) higher on TCP and P compared to the rougher surfaces. The total area of FCs was significantly higher (p < .001) on P surfaces when compared to AE surfaces. Moreover, the number and shape of the FCs differed between P and AE surfaces. Conclusions: These data suggest that compared to the rough surfaces, surfaces with smooth topography promote E-cell growth, spreading, and production of FCs on titanium surfaces. (Supported by CIHR and the ITI Foundation)