Therapeutic effect of ZnO NPs–polyhexanide-hydrogel on Staphylococcus aureus -induced skin wound infection in mice

Nanometer zinc oxide (ZnONPs) offers strong antibacterial, wound healing, hemostatic benefits, and UV protection. Additionally, poly(hexamethylene biguanide)hydrochloride (PHMB) is an environmentally friendly polymer with strong bactericidal properties. However, the synergistic effect of the combination of ZnONPs and PHMB has not been previously explored. The purpose of this study is to explore the synergies of ZnONPs and PHMB and the healing efficacy of ZnO NPs-PHMB-hydrogel on skin wounds in mice infected with Staphylococcus aureus. Therefore, the mice were subjected to skin trauma to create a wound model and were subsequently infected with S. aureus, and then divided into various experimental groups. The repair effect was evaluated by assessing the healing rate, as well as measuring the levels of TNF-α, IL-2, EGF, and TGF-β1 contents in the tissue. On the 4th and 9th days post-modeling, the Z-P group exhibited notably higher healing rates compared to the control group. However, on the 15th day, both the Z-P and AC groups achieved healing rates exceeding 99%. ZnO NPs-PHMB-hydrogel promoted the formation of a fully restored epithelium, increased new hair follicles and sebaceous glands beneath the epidermis, and markedly reduced inflammatory cell infiltration, which was markedly distinct from the control group. On the 7th day, the Z-P group exhibited significantly higher levels of EGF and TGF-β1, along with a considerable reduction in the TNF-α levels as compared with the control group. These results affirmed that ZnO NPs-PHMB-hydrogel effectively inhibits S. aureus infection and accelerates skin wound healing.