Fig. 6: Regulation of cellular behavior through cyclic viscoelastic changes.

a Immunolocalization of YAP (green) and Actin (red) collected following each cycle of regulation under 20 mW/cm² irradiation for 0.5 h, the nuclei outline (blue) is marked in the image. Scale bar: 100 μm. Quantification of cell spreading areas b and circularity c subjected to cyclic viscoelastic regulation alternating for 4 cycles between 0 mW/cm² for 4 hours and 20 mW/cm² light exposure for 0.5 h. n = 36, 68, 135, 102, 117, 157, 134, 144 cells from left to right. **P = 0.0019; *P = 0.013. d Quantification of the YAP nuclear/cytoplasmic ratio. Data were collected from over 60 cells from e in each group, ****P < 0.0001, *P = 0.043. n = 156, 178, 99, 210 cells from three independent hydrogels. e Hey cells were cultured on the slow-relaxing substrate (azure) for 1 to 7 days before being exposed to 20 mW/cm² light, transitioning to fast-relaxing hydrogels (pink). Subsequently, Hey cells were cultured on fast-relaxing hydrogels for 0.5 h or 1 h before collection and analysis (gray). f Cell area response to in situ increasing viscoelastic relaxation (30 min) after different durations of mechanical dosing (1, 3, 5, and 7 days). n = 124, 173, 197, 202, 150 cells (no light, SR1, SR3, SR5, SR7) from three independent hydrogels. g YAP response to in situ viscoelastic changes after 7 days of mechanical dosing on SR-hydrogels. n = 87, 148, 103 (SR7-0 min, 30 min, 60 min) from three independent hydrogels. The solid lines (black) in the scatter plots indicate median values. All statistical analysis was conducted using Kruskal–Wallis with Dunn’s multiple comparisons test.