The determination of the morphology of melanocytes by laser-generated periodic surface structures

We generated self-organized, grating-like structures on the surface of polyethylene-terephthalate by ArF excimer laser ablation. Tilting the polymer films with angles larger than 60°, we got parallel grooves. The surface changes caused by the laser illumination were qualified by AFM. The period of the structures was approximately 1 μm, which is commensurable with the characteristic size of melanocytes. We examined the cell shape of normal epidermal melanocytes (M-C) and of melanocytes from the skin of one neurofibromatosis 1 patient (M-NFS) in vitro. The number of dendrites per cell, the length of dendrites and the orientation of several hundred cells were evaluated by an image-processing program. It was proven that the cell morphology and orientation is determined by the topography of the structured polymer substrate. All cells are aligned parallel to the grooves and show the typical bipolar shape. In contrast, on the untreated part of the substrate, the cells are randomly oriented, and the NF cells have more dendrites.