Figure 1.

Characterizations of MnO₂/GelMA composite hydrogels. The gross morphology of the composite hydrogels is displayed (A). The morphology of MnO₂ (B) was observed by using transmission electron microscopy (TEM). Compressive stress–strain curves (C) and Young’s modulus (D) of the GelMA composite hydrogels with different MnO₂ concentrations were analyzed via compression test, and the morphology of the MnO₂/GelMA composite hydrogels (E) was observed using scanning electron microscopy (SEM). Data are presented as mean ± SD (n = 3). ns p > 0.05; * p < 0.05, versus hydrogels without MnO₂ (GelMA) (D). Representative images are shown. Scale of TEM images = 200 nm (B) and scale of SEM images = 500 μm (E).