Effect of parallel surface microgrooves and surface energy on cell growth

To evaluate the effect of surface treatment and surface mi­ crotexture on cellular behavior, sm ooth and microtextured silicone substrata were produced. The microtextured sub­ strata possessed parallel surface grooves w ith a width and spacing of 2.0 (SilD02), 5.0 (SilDOS), and 10 [xm (SilDIO), The groove depth w as approxim ately 0.5 [xm. Subse­ quently, these substrata were either left untreated (NT) or treated by ultraviolet irradiation (UV), radiofrequency glow discharge treatment (RFGD), or both (UVRFGD). After characterization of the substrata, rat dermal fibroblasts (RDF) were cultured on the UV, RFGD, and UVRFGD treated surfaces for 1, 3, 5, and 7 days. Comparison be­ tween the NT and UV substrata revealed that UV treatment did not influence the contact angles and surface energies of surfaces with a similar surface topography. H owever, the contact angles of the RFGD and UVRFGD substrata were significantly smaller than those of the UV and NT sub­ strata. The dim ension of the surface microevents did not influence the wettability characteristics. Cell culture exper­ iments revealed that RDF cell growth on UV-treated sur­ faces w as lower than on the RFGD and UVRFGD substrata. SEM examination demonstrated that the parallel surface grooves on the SilD02 and SilDOS substrata were able to induce stronger cell orientation and alignm ent than the events on SilDIO surfaces. By combining all of our find­ ings, the most important conclusion was that p h ysico­ chemical parameters such as wettability and surface free energy influence cell growth but play no measurable role in the shape and orientation of cells on microtextured sur­ faces. © 1995 John Wiley & Sons, Inc.