Attachment of fibroblasts on smooth and microgrooved polystyrene

In this study rat dermal fibroblasts (RDFs) were cultured on smooth or micr ogrooved (1-20 mu m wide, 0.5-5.4 mu m deep) substrates. Polystyrene microg rooved substrates were produced by solvent casting on molds that had been p roduced by photolithographic techniques. We investigated the attachment of RDFs with various analytical techniques. Light microscopy and image analysi s showed that RDFs were oriented on most microgrooves. The rate of orientat ion effectively was increased by an increase of groove depth. An analysis o f confluent layers of RDF showed that at confluency microgrooves were able to support greater numbers of cells. However, the largest numbers of cells were not found on the narrowest and deepest microgrooves even though such m icrogrooves have the largest total surface and induce the strongest alignme nt. Interference reflection microscopy (IRM) showed that the RDFs form foca l adhesions where the cell membrane is only 10 nm from the substrate. IRM a lso showed that RDFs follow the contours of shallow and wide microgrooves b ut bridge the grooves on deeper and narrower ones. This could explain why s uch grooves are not able to increase the numerical cell adhesion to a great er degree. The absence of contact between cells and the bottom of the groov es is a very important factor in establishing contact guidance. (C) 1999 Jo hn Wiley & Sons, Inc.