MALDI-MSI-PBC workflow. First, wax patterns were printed onto Whatman 105 lens paper. Next, the zones of the patterned scaffolds were seeded with either cell-laden Matrigel or Matrigel only. After an overnight incubation in culture medium, the scaffolds were dried using a vacuum centrifuge and then mounted onto a MALDI target plate with double-sided conductive tape. Next, the drug solutions were spotted onto selected wells and allowed to redry. Matrix was then applied using a robotic sprayer. Finally, the scaffolds were analyzed with MALDI-MSI to generate the ion density maps.