Fluorescence microscope images (a–f) of the actin cytoskeleton (red) and the cell nuclei (green) of ST2 cells in a PCL-PEG ADA-GEL construct after 28 days of incubation of different magnification: (a,b) overview images; (c) densely packed area of the cells covering both materials; (d) cell morphology on the hard phase; (e) cell agglomerate and spread single cells in hydrogel; and (f) densely packed area of cells (hydrogel phase) [1]