A novel composite polydopamine-based hydrogel dressing that heals diabetic ulcers

• A novel polydopamine-based hydrogel was developed for diabetic wound healing. • The hydrogel exhibits broad-spectrum antibacterial activity via dual antibacterial mechanisms. • It effectively scavenges ROS and alleviates oxidative stress in chronic wounds. • The hydrogel modulates macrophage polarization to promote anti-inflammatory responses. • It enhances angiogenesis and accelerates diabetic foot ulcer healing in vivo. • The hydrogel offers a multifunctional, translational approach for infected chronic wound care. The current treatment of diabetic foot ulcers remains a great challenge due to the persistent chronic inflammatory trauma microenvironment caused by oxidative stress, elevated levels of inflammatory factors, impaired angiogenesis, and bacterial infection. However, current therapeutic strategies primarily focus on wound closure rather than addressing the underlying pathophysiology of diabetic wounds. Therefore, there is an urgent need for advanced wound dressings that not only promote wound closure but also modulate the wound microenvironment to accelerate tissue regeneration. Here, we report a multifunctional hydrogel dressing that can be conveniently fabricated through copolymerization of a complex formed by a polydopamine–polyethyleneimine hybrid coating (PDA–PEI) and GelMA. This hydrogel exhibits excellent mechanical strength, tissue adhesion, and self-healing capacity. It demonstrates antibacterial activity, alleviates oxidative stress and inflammation, promotes angiogenesis, regulates macrophage polarization, and enhances full-thickness skin regeneration in MRSA-infected diabetic mice. The article highlights the potential of this hydrogel as a promising therapeutic strategy for improving the clinical management of diabetic foot ulcers.