A novel antibacterial hydrogel based on thiolated ovalbumin/gelatin with silver ions to promote wound healing in mice

Hydrogels could be used as wound dressings, but most protein-based hydrogels lack anti-bacterial effects. Here, we successfully prepared a silver ion cross-linked thiolated protein hydrogel (thiolated Ovalbumin and Gelatin, O3G7). The wound photographs showed that the healing rate (96.23 %) of hydrogel-treated mice was higher than the control group. Meanwhile, the hydrogel increased the granulation tissue's total protein content. Furthermore, it significantly increased the collagen content, consistent with the results of Masson's trichrome (MT) staining and immunohistochemical analysis of type I collagen (Col-I). The results of hematoxylin and eosin (H&E) staining showed the growth and proliferation of inflammatory cells, granulation tissue, fibroblasts, blood vessels and hair follicles in acute wounds. O3G7 hydrogel had fewer inflammatory cells and more neovascularization, and hair follicle tissue and intact epidermis could be observed. The results of immunofluorescence and immunohistochemistry showed that the O3G7 group reduced the expression of tumor necrosis factor (TNF)-alpha (56.87 % of the control group) and upregulated the expression of transforming growth factor (TGF)-beta (1.29 times of the control group). These results suggest that O3G7 hydrogel significantly affects the healing of acute wounds. This study demonstrates that hydrogels prepared from food-derived proteins will be promising and bio-safe candidates in bioengineering.