Fig. 6
Analysis of actin stress fibers and paxillin patches of 3T3 cell incubated for 24 h on fibronectin-coated PAA gels. a Confocal images of paxillin (green), actin (blue) and nuclei (pink) staining of 3T3 cells sitting on an elastic gel (top) and a viscoelastic gel (bottom) coated with 100 µg/ml fibronectin on the crosslinked network and the linear PAA. Scale bars = 20 µm, insets are magnification x3 of the dotted boxes. b Confocal images of paxillin (green), actin (blue) and nuclei (magenta) of 3T3 cell sitting on an elastic gel (top) and a viscoelastic gel (G” = 500 Pa, bottom) coated with 100 µg/ml fibronectin on the crosslinked network of PAA. Scale bars = 20 µm, insets are magnification x3 of the dotted boxes. c Confocal images of paxillin (green), actin (blue) and nuclei (magenta) of 3T3 cell on a 5 kPa viscoelastic gel presenting fibronectin on the linear PAA. Scale bars = 20 µm, insets are magnification x3 of the dotted boxes. d Percentage of cells containing stress fibers on elastic and viscoelastic gels as a function of G” and the type of PAA presenting fibronectin. Sample size: NHS 0 Pa n = 22 cells, NHS 500 Pa n = 20 cells, sulfoSANPAH 0 Pa n = 24 cells, sulfoSANPAH 500 Pa n = 27 cells. e Percentage of cells containing paxillin clusters as a function of G” and the type of PAA presenting fibronectin. Sample size: NHS 0 Pa n = 22 cells, NHS 500 Pa n = 20 cells, sulfoSANPAH 0 Pa n = 24 cells, sulfoSANPAH 500 Pa n = 27 cells. f Average number of paxillin patches by cell as a function of the value of G” and the type of PAA presenting fibronectin. Sample size: NHS 0 Pa n = 22 cells, NHS 500 Pa n = 20 cells, sulfoSANPAH 0 Pa n = 24 cells, sulfoSANPAH 500 Pa n = 27 cells. Error bars represent the standard error. g Size of paxillin clusters as a function of G” and the way to present collagen I to the cells. Sample size: NHS 0 Pa n = 22 cells, NHS 500 Pa n = 20 cells, sulfoSANPAH 0 Pa n = 24 cells, sulfoSANPAH 500 Pa n = 27 cells. ***Statistically significant differences with a p-value of <0.01, as calculated by non-parametric Tukey's tests
