Bacteria-triggered autonomous programmed adaptive theranostic bilayer self-healing hydrogels for accelerated healing of infected wound

Innovative platforms integrating real-time point-of-care testing (POCT) with condition-adaptive therapy are urgently required for intelligent theranostics in microbially infected wounds. To address this dual challenge, we engineered a bilayer, stimuli-responsive, multifunctional self-healing hydrogel. The hydrogel is composed of polyvinyl alcohol (PVA), dextran (Dex) and borax, which enables rapid self-healing Encapsulating pH-responsive borax/tannic acid (BT) complexes and bromothymol blue (BTB) dye within the hydrogel, the POCT layer affords a visible colorimetric response within a pH detection range of 5.5–8.5. This sensitivity enables the correlation of pH changes with the concentration of five common pathogens, facilitating in situ , real-time evaluation of wound infection progression. By incorporating CaO 2 nanoparticles and FeS 2 nanozymes into the hydrogel, the therapeutic layer is obtained. Activated by the acidic microenvironment of infection, it generates H 2 O 2 to various reactive oxygen species (ROS). ROS is integrated with inherent photothermal property to achieve synergistic antibacterial therapy, achieving nearly 100% sterilization rate against Escherichia coli and M. luteus . In the post-infection phase, the composite hydrogel exhibits self-awareness of the wound microenvironment. The hydrogel initiates self-driven O 2 release to relieve oxidative stress and accelerate wound healing. In vivo experiments, the multifunctional hydrogel resulted in 89.03% wound healing rate in MRSA -infected wounds. This smart design not only enables timely POCT and treatment of infected wounds but also facilitates adaptive modification of therapeutic protocols in accordance with the severity of the infection. The highly adaptive hydrogels are anticipated to provide a novel approach with great potential for designing intelligent theranostic platforms, enabling real-time monitoring of infection degree, efficient antimicrobial therapy, and promotion of wound recovery.