Fig. 3: Impact of force stimulation on cell migration in DexMA 3D hydrogels.
a–c Representative brightfield and fluorescence images of cells in a DexMA 3D hydrogel grafted with CD-PNIPAM-RGD. (a), CD-PDMA-RGD (b), PNIPAM-RGD (c) each with a molecular weight of 15 kDa under 9.2 μW/μm2, 10 Hz NIR illumination Cells were tracked over time during NIR illumination. The illuminated area is demarcated by a dashed red circle. Scale bars = 50 μm. Incubation temperature = 25 °C. Actin and nuclei are visualized as green and blue, respectively. d Graph depicting the mean relative increase in sprout length of spheroids encapsulated in hydrogels conjugated with CD-PNIPAM-RGD over time, within two defined regions of interest: ROI1(NIR illuminated) and ROI2 (non-illuminated). n = 55, 47 cells respectively. ***P < 0.001 e–f Identical experiments conducted with control hydrogels functionalized with CD-PDMA-RGD (e) and PNIPAM-RGD (f), respectively. ROI1(NIR illuminated) and ROI2 (non-illuminated). n = 55, 64, 57, 56 cells from left to right. ns p = 0.32835, 0.40963. Data was collected from at least 12 cell spheroids across three independent experiments. g Fluorescence imaging showing the expression of actin (grey), vinculin (green) and integrin αVβ3(red). Scale bars = 200 μm for 10× photo, 20 μm for magnified photos. h A significantly higher proportion of cells formed FAs after 4 cycles of illumination. Cells with focal adhesion were statistical results from 3 independent experiments, 3 spheroids each. The data in (d–f, h) is presented as mean values ± S.D. Data from non-illuminated and illuminated areas within each condition were compared using an unpaired one-tailed Student’s t-test.
