Bacterial infection and oxidative stress remain critical problems for
wound closure because they frequently trigger severe complications and delay wound healing. In addition, maintaining a moist microenvironment can promote skin regeneration. In this study, a bilayer
hydrogel modified with
tannic acid (TA) was constructed to accelerate
wound repair. The bilayer
hydrogel, composed of a layer with large pores to absorb the fluids and allow gas exchange and small pores to maintain the
wound moist and prevent bacterial invasion, was initially developed. Thereafter, TA was introduced into the
hydrogel to form a dual crosslinked network and endowed the
hydrogel with adhesiveness, antibacterial, and oxidation resistance. In addition, the TA@bilayer
hydrogel exhibited shape memory behaviour and self-healing ability due to the hydrogen bonds formed between TA and the bilayer
hydrogel. As a result, the TA@bilayer
hydrogel significantly promoted
wound closure by accelerating
collagen deposition, reducing tumour
necrosis factor-α (TNF-α) levels, and facilitating the expression of
vascular endothelial growth factor (
VEGF).