Figure 6. (A)Representative H&E-stained images and Masson’s trichrome staining image of the wounds on day 7. Bar, 500 μm. Representative images of wounded (day 7) skin stained to show the expression of (B) CD31 (green) and α-SMA(red) in the wounds (blue); (C) CD86 (green) and CD163 (red) in the wounds (blue). Bar, 100 μm.
As shown in Figure 6B and 6C, to further analyze the enhancement effect in wound recovery, the immunofluorescence staining of wound tissues on day 7 were processed. In the proliferation phase, the occurrence of neovascularization is critical to ensure the transport of nutrients and oxygen to the wound site to sustain fibroblast proliferation, collagen synthesis, and re-epithelialization. Immunostaining of the platelet endothelial cell adhesion molecule-1 (CD31) can assess the presence of newly generated vessels in the granulation tissue. The α-smooth muscle actin (α-SMA) is closely related to the proliferation of fibroblasts. The wound sections from the ANVs and THB@ANVs hydrogel groups had more CD31 and α-SMA compared to the control group. This result suggests that THB@ANVs hydrogel can enhance the healing process more rapidly. Furthermore, CD86 and CD163 staining verified that the M2/M1 macrophage of THB@ANVs hydrogel group is the highest among all groups, demonstrating the wound healing had entered to proliferative phase earlier than other groups.