Solar-simulated light-driven ROS-responsive CuₓO-TiO_2-X microneedle patch for intelligent antibacterial and...

Burn wounds infected with Staphylococcus aureus (S. aureus) are often characterized by excessive early inflammation, which leads to persistent oxidative stress, pain, and delayed healing. To overcome the limitations of conventional photosensitizers, which may induce reactive oxygen species (ROS) overload and subsequent tissue damage, we developed a ROS-responsive microneedle patch (TC@MN). This system consists of chlorogenic acid-based microneedles encapsulating a CuₓO-TiO_2-X (TC) nanozyme heterostructure designed for synergistic antibacterial and regenerative therapy. TC@MN exhibits intrinsic peroxidase-like (POD) and catalase-like activities (CAT). Under light irradiation, these catalytic processes participate in ROS regulation and promote Cu²⁺/Cu⁺ redox cycling, leading to the generation of bactericidal •OH and •O₂⁻ radicals while simultaneously producing O₂ to alleviate local hypoxia. In animal experiments, TC@MN scavenges excess ROS and promotes macrophage polarization toward the M2 phenotype thereby facilitating inflammation resolution and tissue repair under light-free conditions. Collectively, this light/dark dual-mode microneedle platform integrates photocatalytic and enzyme-mimetic functions, offering a biocompatible and intelligent strategy for the treatment of infected burn wounds.