Metal-phenolic network functionalized polydopamine nanoparticles promote diabetic wound healing via enhanced photothermal effect.

Diabetic wounds represent one of the most devastating complications of diabetes mellitus, characterized by delayed or non-healing outcomes arising from the complex pathological microenvironment, including vascular impairment, excessive inflammation, and persistent infection. To achieve simultaneous modulation of the multiple pathological features underlying diabetic wounds, herein we developed polydopamine nanoparticles surface-functionalized with copper-tannic acid metal-phenolic networks (PDA@Cu-TA). PDA@Cu-TA improves the photothermal conversion efficiency of pristine PDA. Benefiting from the chelating effect of Cu-TA and the strong adhesion of PDA, this composite material achieves responsive sustained release of Cu2+, which greatly elevates its biosafety. In addition, the combination of released Cu2+ and mild photothermal treatment exhibits outstanding antibacterial capacity and markedly facilitates neovascularization. In vitro studies demonstrated that PDA@Cu-TA exhibited excellent antioxidant, anti-inflammatory, pro-angiogenic, and antibacterial activities, along with outstanding biocompatibility.In vivo experiments further confirmed that PDA@Cu-TA significantly accelerated wound closure in diabetic mice.Collectively, this study presents a multifunctional nanoplatform that enables synchronous regulation of the diabetic pathological microenvironment for effective wound repair via mild photothermal therapy.