(A) Schematic of study strategy for examining the angiogenic potential of AHA-HT1080 constructs: HT1080 cells, SDF1α, and S1P were encapsulated in AHA hydrogels of different stiffnesses and cultured for 24 hours in hypoxic or atmospheric conditions, followed by seeding of ECFCs as a monolayer on top of the hydrogels and culturing for an additional 24 hours. (B) Lectin stain (in red) and side-view imaging of endothelial sprouting in medium hydrogel in atmospheric and hypoxic conditions. (C) Quantification of sprouting length of ECFCs in the different stiffness and oxygen tension conditions. Significance levels (n=3) were set at: *p<0.05, **p<0.01, and ***p<0.001.