Cell viability assays and immunocytochemistry. The tests were performed on 3D printed square scaffolds (bounding box 100x100 µm, z-height: 5 µm) fabricated by two-photon laser 3D prin ng with a laser power of 20 mW and a scanning speed of 14000 µm s -1 . Arrays of 5x5 pedestals with 200 µm distance were prepared. Prior to cell culture, the cell scaffolds were sterilized with ultraviolet (UV) light for 30 min and coated with fibronec n (10 µg/mL) purchased from Sigma-Aldrich (St. Louis, MO, USA).