Immunoregulatory hydrogel decorated with Tannic acid/Ferric ion accelerates diabetic wound healing via regulating Macrophage polarization

•Immunomodulatory hydrogel was successfully prepared via one step polymerization.•Hydrogel showed excellent cytocompatibility, antioxidant, antibacterial ability.•Hydrogel promoted M2 polarization by activating PI3K/Akt signaling pathway.•Hydrogel improved diabetic wound healing by regulating immune microenvironment.