Silk mat with 4-hexylresorcinol (4HR) implantation animal model (n = 5 for each group). (A) Results of immunohistochemical analysis showed that expression of vascular endothelial growth factor (VEGF) and angiogenin was higher in the group treated with silk mats containing 4HR than in the group treated with silk mats alone. (B) VEGF-A and angiogenin expression were higher in both groups treated with silk mats with or without 4HR than in the control group (error bar = standard deviation, *P < 0.05). (C) Western blot from collected tissue samples. The results of western blotting were consistent with those of immunohistochemical analysis (cropped blot from different gels). Expression of VEGF-A, VEGF-C, and angiogenin increased in the group treated with silk mats containing 4HR (1: unfilled control, 2: silk mat alone, 3: silk mat with 10% 4HR, 4: silk mat with 20% 4HR).