Figure 6.

The effect of tissue and tumor microenvironment elastic modulus on metastatic migration of HCT116 cells in 3-D. A: Using acrylate-functionalized PEG-based crosslinkers of varying geometry allows for manipulation of hydrogel-based construct and tumor mechanical properties. Rheological data demonstrates statistically different (*P < 0.05) shear elastic moduli of hydrogels created using these crosslinkers. B: HCT116 cells were embedded in a central stiff gel core of 4.5 kPa surrounded by soft 100 Pa hydrogel-based tissue construct (left), or in a soft 100 Pa core surrounded by a stiff 4.5 kPa hydrogel-based tissue construct (right). C: Top-down, D) side, and (E) isometric macroconfocal images of tumors and space above the tumors. Stiff-core, soft environment tumors grow, but remain primarily at the tumor’s location. Soft-core, stiff environment tumors exhibit increased migration outwards from the tumor into the stiff environment in the form of large multicellular protrusions and aggregates.