Figure 1.

Discretized O₂‐gradients facilitate study of cell behavior in refined 3D microenvironments. A) Computational model of layered hydrogels showing bottom (severely hypoxic), middle (moderately hypoxic), and top (nonhypoxic) layers. B) Cells were encapsulated in bottom (B; severely hypoxic), middle (M; moderately hypoxic), and top (T; nonhypoxic) layers. Representative O₂ measurements are shown. C) Distinct cell morphology was observed in each layer. Cells in the T layer exhibit single cell vasculogenesis (i); cells in the M layer exhibit cluster formation and vascular sprouting from clusters (ii); and cells in the B layer exhibit cluster formation (iii). Images were captured at D3 (72 h) after cell encapsulation. All scale bars: 100 µm.