HDF cells were cultured on the surfaces of 0.5 wt % peptide gels or 0.3 wt % collagen gels in Essential 8 Medium for 4 days. (a) Live and dead cells were visualized using calcein AM and ethidium homodimer-1 staining (scale bar = 100 μm), respectively. (b) Cell proliferation was monitored by quantifying cell viability using a WST-8 assay on days 0, 1, and 4. Data are represented as mean ± standard deviation (SD) of three independent replicates. (c) Cytoskeleton organization and focal adhesions were stained on day 1 against actin (green), vinculin (red), and nuclei (blue, scale bar = 100 μm).