A SIKVAV-modified chitosan hydrogel promotes the contraction of skin wounds in mice: (A) Typical photoimages of the general wounds of control, SIKVAV, chitosan, and SIKVAV-modified chitosan group mice on days 3, 5, and 7 after trauma. (B) Statistical analysis of the residual wound percentage of mice in the control, SIKVAV, chitosan, and SIKVAV-modified chitosan groups (n = 6, * p < 0.05, and ** p < 0.01). (C) Immunohistochemistry showing the expression of α-SMA in the skin wounds of the control, SIKVAV, chitosan, and SIKVAV-modified chitosan group mice on days 3, 5 and 7 after trauma (scale bar: 50 μm). (D) Statistical analysis of α-SMA in the skin wounds of mice in the control, SIKVAV, chitosan, and SIKVAV-modified chitosan groups on days 3, 5 and 7 after trauma (n = 3, * p < 0.05, and ** p < 0.01).