3.8. RHC/EGF promotes neovascularization of wound skin
Neovascularization is necessarily required for normal tissue development, particularly to provide oxygen and nutrition to granulation tissues. CD31 is found on the surface of endothelial cells and is widely used as a marker of angiogenesis.(Camila et al.) VEGF, as a marker of angiogenesis, can enhance vascular permeability and promote the formation of capillaries in new blood vessels.(Jelena et al.) Damaged skin was collected on days 3 and 14 and the expression of CD31 and VEGF in vascular network was assessed by IHC (Fig. 6). After treatment for 3 or 14 d, expression of CD31 was significantly increased in EGF and RHC/EGF groups compared with control and RHC groups. At the same time points, VEGF expression exhibited the same trend. As angiogenesis biomarkers, upregulation of CD31 and VEGF demonstrates that RHC/EGF can accelerate wound healing and repair. Therefore, RHC/EGF freeze-dried can promote wound healing by promoting angiogenesis. Local application of growth factors such as bFGF, EGF, and VEGF are the most common methods to promote wound healing by promoting angiogenesis.(Qu et al.; Xue, Zhao, Lin, & Jackson) However, skin defect repair is a complex process that requires the synergistic effects of cell adhesion, spread, migration, and angiogenesis. As a result, many of these growth factors fail to achieve complete wound healing. In addition, collagen has a good role in promoting cell adhesion and migration, but has the disadvantages of poor solubility and easy to cause immune response Therefore, we prepared RHC/EGF freeze-dried while promoting adhesion, diffusion, migration, and angiogenesis. In summary, RHC/EGF promotes cell adhesion, proliferation, migration, and angiogenesis in vitro. In vivo, RHC/EGF freeze-dried accelerate wound healing by enhancing re-epithelialization, promoting collagen deposition and angiogenesis. Therefore, RHC/EGF freeze-dried may be a promising dressing for wound healing.