Bacterial Microenvironment‐Responsive Microneedle Patches for Real‐Time Monitoring and Synergistic Eradication of Infection

Abstract Bacterial infection stands as one of the biggest threats to public health. In recent years, the rise of diverse drug‐resistant bacteria has significantly compromised the efficacy of existing antibiotics in eradicating them, and the formation of biofilms has further weakened the treatment effect. In this study, a pH‐responsive photodynamic probe, TI, is developed and assembled with a ROS‐reactive carbon monoxide (CO) donor, and then encapsulated within a HA‐based microneedle patch, ultimately creating the theranostic microneedle platform. The microneedle structure enhances the mechanical penetration of both the molecular probe and CO donor into the biofilm at the site of wound infection. When encountering the acidic microenvironment of the wound, TI undergoes dynamic molecular structural changes, resulting in a notable near‐infrared fluorescent output for detecting infections and assessing their severity. Concurrently, the nanoprobes unleash their ROS‐generating potential, which can not only directly eliminate bacteria through oxidative damage, but also trigger the release of CO for adjunct gas therapy. Overall, the integrated diagnostic and therapeutic microneedle platform provides a promising approach to addressing wound infections, and alleviating the challenges posed by antibiotic resistance, offering significant hope in the realm of infection care management.