Figure 2. Characteristics of the formulated A-SA-Gel hydrogel and the 3D printed scaffolds from the hydrogel: (A) The viscosity of the hydrogel that has a shear thinning behavior. (B) The modulus of the crosslinked hydrogel that has a higher storage modulus than that of loss modulus. (C-D) Photograph of the 3D printed hydrogel scaffold (top view) and its side view. (E) SEM micrographs of the top view of the printed scaffold (white dotted line indicate the different layers of the scaffolding system, scale bars: 500 μm), (F-G) corresponding magnification of C (scale bars: F=500μm, G=250μm), (H) the filaments of different layers of the scaffold (scale bars:250μm), (I) cross-sections morphology of the scaffold (scale bars:250μm), (J) a close view of morphology of the scaffold (scale bars:50μm), and (K-M) SEM images of the surface of a single printed filament (scale bars: K=250 μm,L=100μm,M=25μm).