Dual-functional chameleon microneedles based on Cel/Fe-GA-OKGM/Gel for programmed biofilm eradication and real-time healing surveillance in chronic wounds

Wound dressings play a critical role in wound management, yet engineering specialized solutions for biofilm-compromised chronic infections remains a formidable challenge. To address this, we developed a cellulase (Cel)-integrated hydrogel microneedle (MN) patch—comprising gallic acid (GA)-grafted oxidized konjac glucomannan (GA-OKGM), gelatin (Gel), and iron ions (denoted as Cel/Fe-GA-OKGM/Gel MNs)—for the programmed therapy and monitoring of chronic infected wounds. This hydrogel system features dual crosslinking via Fe-phenolic hydroxyl coordination bonds (GA-Fe) and Schiff base linkages (OKGM-Gel). By leveraging the physical penetration of MNs, surface-loaded cellulase efficiently degrades biofilms, thereby overcoming biofilm-mediated antimicrobial resistance. In vivo and in vitro studies demonstrate that these MNs exhibit potent biofilm-disrupting, antibacterial, anti-inflammatory, antioxidant, and macrophage-polarizing properties, collectively reprogramming the wound microenvironment to accelerate healing. Furthermore, the GA-Fe complex undergoes microenvironment-dependent chromatic transitions within wounds, serving as a real-time visual biomarker that dynamically reflects the progression of healing and infection status. This dual-functional “chameleon” system thus holds exceptional promise for the precise management of chronic infected wounds and future clinical translation.