Figure 1.

Schematic overview of experimental approach

To compare possible different influences of Dll4 vs Jag1 patterns on endothelial sprouting, the method previously described in Tiemeijer et al. (2018) was adapted.

(A–C and E) In short, microcontact printing (μCP) stamps (A) were inked with fluorescent beads functionalized with either Dll4 or Jagged1, and lines of 100 μm with 100 μm spacing were printed on glass slides (B). (D) In addition, endothelial cells were seeded on top, via microfluidic channels (C and C2) perpendicular to the lines. After channel removal, Matrigel was added, and the endothelial cells were left to sprout freely for 24 h. With respect to the ligand-functionalized lines, we envision the possibility of three different spatial sprouting patterns (E), random, positive, and negative patterning. Scale bar represents 1mm.