Healing mechanism of cotton bandage loaded with PNIPAM/GO-Ag hydrogel on the deep second-degree burn wound in rats model

Dressings play a crucial role in the management of burn wound. In this study, the cotton bandage was modified with the Poly (N-isopropylacrylamide) / graphite oxide/nano silver (PNIPAM/GO-Ag) hydrogel to obtain a novel dressing (PNIPAM/GO-Ag/COT). The healing effect of the PNIPAM/GO-Ag/COT dressing on deep second-degree burn wounds in rats and the changes of related inflammatory factors were explored and analyzed systematically. The deep second-degree burn model was established by the steam scald method in Sprague–Dawley (SD) rats. The granulation tissue, collagen deposition, the expressions of tumor necrosis factor-α (TNF-α), and basic fibroblast growth factor (bFGF) of the wound were evaluated by means of the HE staining, Masson staining, ELISA, and immunohistochemistry methods. The results showed that, compared with the blank group (rats without the dressing treatment), the PNIPAM/GO-Ag/COT dressing reduced the expression of TNF-α by approximately 18 % and promoted the bFGF expression in wound tissue. Compared to the control group (rats with the gauze treatment), the wound healing rate in the PNIPAM/GO-Ag/COT dressing group was 58 % on the 14th day, with an increase of 30 %. These results demonstrated that the PNIPAM/GO-Ag/COT dressing primarily promoted burn wound healing by reducing inflammatory reactions, promoting collagen deposition, and enhancing the expression of bFGF.