Spray-deployable microenvironment-adaptive nanozyme interface for anti-biofilm and redox-regulated chronic wound healing

Chronic wounds are characterized by persistent bacterial infection, oxidative stress, and impaired tissue regeneration, which require dynamic therapeutic interventions throughout the healing process. Herein, we report a spray-deployable nanozyme hybrid multifunctional dressing (MHFD) based on Fe 3 O 4 /Au magnetic-gold nanozymes integrated into a polydopamine/phase-transition bovine serum albumin (PDA/PTB) interface. The PDA/PTB hybrid membrane not only stabilizes the catalytic interface and inhibits bacterial adhesion but also enhances nanozyme activity and photothermal responsiveness. Benefiting from the pH-responsive catalytic behavior of Fe 3 O 4 /Au nanozymes, the MHFD exhibits peroxidase (POD)-like activity under acidic infection conditions for efficient bacterial eradication, while switching to superoxide dismutase (SOD)-like activity under near-neutral conditions to alleviate oxidative stress and promote tissue repair. The synergistic effects of anti-adhesion, catalytic antibacterial activity, redox regulation, and photothermal enhancement enable effective control of the wound microenvironment. Both in vitro and in vivo studies demonstrate that MHFD accelerates infection resolution, promotes macrophage polarization and collagen deposition, and significantly enhances chronic wound healing. This work provides a versatile interfacial engineering strategy for constructing multifunctional nanozyme-based therapeutic platforms.