Coculture of ECs with PCs and ACs. (A) Dual coculture of ECs with ACs. AC density in coculture varied between 1:1 and 1:16 ratios. The presence of ACs alone did not significantly affect endothelial network area. Scale bar: 0.5 mm. Red: ECs. Green: ACs. (B) Dual coculture of ECs with PCs. PC density in the coculture varied between 1:80 and 1:5 PCs:ECs ratios. A PCs:ECs ratio of 1:20 saw a significant increase in endothelial network area compared with EC-only controls, indicating increased coverage of the hydrogel with more robust vascular networks. Higher PC densities—1:5 and 1:10 PCs:ECs ratios—saw the formation of confluent cell sheets. Scale bar: 0.5 mm. Red: ECs. Green: PCs. (C) Triple coculture of ECs, PCs, and ACs. A number of conditions resulted in a significant increase in network area compared with an EC-only control, but without the formation of confluent cell sheets. Scale bar: 0.5 mm. Red: ECs. Green: ACs. *p < 0.05 compared with EC-only controls, Dunnett's multiple comparisons test. #Conditions where dual coculture formed confluent cell sheets. Color images are available online.