A pyramid microarray comprising microsized nanowires made by 3D corner lithography is presented by N. R. Tas and co-workers on page 3823. The arrays are integrated into a cell-seeding device for the entrapment of single cells. Polystyrene microspheres are shown efficiently captured from a suspension of homogeneously shaped spheres. The same procedure is done with a suspension of primary bovine chondrocytes, after which their phenotype is studied over 48 h. The magnified electron micrograph shows the efficient entrapment of 1 cell per pyramid after 2 h of cell culture. Cells maintain their native round morphology during entrapment, while the onset of protein deposition starts between these confined cells.