Transmission Electron Microscopical Study of Fibroblast Attachment to Microtextured Silicone Rubber Surfaces

Cellular attachment has been suggested to be highly influenced by the micromorphology of the substratum surface. To test this hypothesis, smooth and microtextured silicone substrata were produced, which possessed parallel surface grooves with a groove and ridge width of 2.0 (SilD02), 5.0 (SilD05), and 10 µm (SilD10). Groove depth was approximately 0.5 µm. After culture of rat dermal fibroblasts (RDFs) on these substrata for 3 and 5 days, the samples were prepared and sectioned for transmission electron microscopy with a specially developed preparation technique. On the SilD02 and SilD05 surfaces, it was found that the RDFs attached to the ridges of the surface pattern and did not contact the bottom of the surface grooves. In some instances cell protrusions extended into the grooves, but none of these cell extensions were found to contact or attach to the bottom of the microgrooves. Focal adhesion points were observed on the ridges of the surface patterns. In contrast, on the SilD10 substrata focal adhesion points were observed on the surface ridges as well as in the surface grooves. Furthermore, close examination of the cytoskeletal structures suggested orientation of the filamentous cytoskeletal components parallel to the surface grooves on the SilD02 and SilD05 surfaces, which might be related to observed overall cellular alignment along parallel surface grooves