Multifaceted Microneedle Patch: A One-Stop Solution to Combat Multitype Wound Infections

Bacterial-infected wounds impose a substantial burden worldwide, with polymicrobial infections exacerbating the complexity of healing through dysregulated pH environments and gelatinase-mediated matrix degradation. Herein, we developed a microenvironment-responsive microneedle (MN) patch utilizing a "dynamic warning-graded intervention" strategy. The patch incorporates (a) a bromothymol blue-based pH visual warning system that detects acid-base changes during both acute and chronic infections, (b) a gelatin methacryloyl and exosome matrix material that enables enzyme-triggered release of human bone marrow mesenchymal stem cell-derived exosomes, responding to pathological gelatinase for spatiotemporal drug delivery, and (c) triple therapeutic payloads [hemostasis (halloysite nanotubes)/antibacterial and anti-inflammatory (antimicrobial peptides)/scar reduction (salvianolic acid B)]. In vitro validation demonstrated a bacterial clearance rate exceeding 95% against methicillin-resistant Staphylococcus aureus/imipenem-resistant Pseudomonas aeruginosa, with biofilm inhibition and disruption rates both surpassing 90%. In vivo experiments demonstrated that MNs showed observable changes in wound color within 8 h in both infectious acute and chronic wounds. In acute wounds, nearly complete healing was achieved within 10 d. By coordinating hemostasis (platelet activation within 60 s), controlling inflammation (62.07% down-regulation of tumor necrosis factor-α), and promoting angiogenesis (2.51-fold up-regulation of CD31), the healing rate of diabetic ulcers was accelerated by 9.20% compared to clinical dressings. This platform provides a foundation for integrating real-time diagnosis and treatment in complex wound management.