Testing 3D PLA printed devices for neurite patterning: (A) Blueprint of the coverslip. (Model 009), (B) Cultured neurons were immunostained with mouse anti-betaIII tubulin and with phalloidin for actin, and DAPI for nuclei. Images were taken with a 3i spinning disk system at 20×. The specific axon marker betaIII tubulin shows that cell bodies are excluded from a region of the coverslip by the unshielded plastic. This carpet of axons is clearly identifiable and uniform. Phalloidin staining of actin shows the distribution of growth cones on the sample. DAPI staining shows neuronal cell bodies are strongly concentrated outside the obstacle. (C) Quantification of neuronal density in Model 009 chamber. In the open field, DAPI positive nuclei were detected at about 12 per 30 μm square, whereas the central region for visualizing axons is almost completely devoid of nuclei. A border region between the open chamber and the centre of the axon visualizing region extends for approximately 200 μm, where some DAPI-positive cell bodies have migrated under the height barrier. In this boundary region, cells are about 50% the density of the open field.