Carbon-dot nanozyme-empowered responsive hydrogels for smart wound dressing

• A smart hydrogel wound dressing was fabricated via a simple, scalable method. • Embedded carbon dots act as both pH-sensitive fluorescent sensors and nanozymes. • The hydrogel offers dual-mode therapeutic release. • The dressing demonstrates excellent cytocompatibility and promotes fibroblast growth. • The system protects cells from damage induced by reactive oxygen species (ROS). Smart wound dressings that enable real-time monitoring and responsive therapeutic delivery are essential for advancing personalized wound care. In this work, we present a scalable strategy to develop a multifunctional hydrogel patch by embedding carbon dots (C-dots) into an ionically crosslinked sodium alginate (SA) matrix. The C-dots serve dual roles by providing visible, pH-responsive fluorescence for wound monitoring and functioning as superoxide dismutase (SOD)-like nanozymes to scavenge reactive oxygen species (ROS). The patch’s optical transparency, pH sensitivity, swelling capacity, and mechanical strength can be tuned by varying the C-dot content. Structural analyses using scanning electron microscopy, Fourier-transform infrared spectroscopy, and synchrotron small-angle X-ray scattering reveal hydrogen bonding between C-dots and alginate chains, which underpins the dual stimulus-responsive behavior of the developed hydrogel patch. The patch autonomously releases C-dot nanozymes in response to microenvironmental cues and also allows on-demand release upon gentle mechanical pressure, addressing diverse wound care needs. In vitro studies confirm excellent cytocompatibility, enhanced fibroblast proliferation, and protection against ROS-induced damage. This smart, dual-responsive hydrogel patch presents a promising platform for next-generation wound dressings, suitable for chronic wound management and point-of-care wound management.