Fig. 2.
Preparation and characterization of PAA-RGD, PEG-RGD, and GelMA hydrogels. (a) Cartoon illustration of the PAA-RGD hydrogel formation. (b) Strain-stress curves of the hydrogels in the compression study. (c) Swelling curves of the hydrogels (P < 0.001). (d) Protease K-induced degradation rate of PAA-RGD, PEG-RGD, or GelMA hydrogels in vitro (P < 0.001). (e) Representative SEM images of the hydrogels. Scale bars, 100 μm. The polymer content was fixed at 10 wt% for all of the hydrogels. Statistical significance was calculated using one-way ANOVA with Tukey's post-hoc test. ***P < 0.001.