Fluorescent Microneedle‐Based Theranostic Patch for Naked‐Eye Monitoring and On‐Demand Photo‐Therapy of Bacterial Biofilm Infections

Abstract The eradication of recalcitrant bacterial biofilm infections necessitates the development of speedy diagnostics and prompt therapeutics. However, constructing a portable versatile platform that enables in situ monitoring of biofilm infections accompanied by potent antibiofilm activity remains challenging. To address this conundrum, a microneedle theranostic patch (Mn: C/G@MN) is devised by incorporating an innovative biophotonic probe (manganese‐doped carbon dots, Mn: CDs) into methacrylated gelatin for visual monitoring of biofilm infection and on‐demand photo‐therapy. The Mn: C/G@MN patch penetrates the physical barrier of biofilms to track their acidic microenvironment, exhibiting a visualized fluorescence color change (from yellow to turquoise) to enable naked‐eye monitoring of biofilm infection. Furthermore, the Mn: C/G@MN patch can drastically eradicate biofilm on‐demand through the synergy of local hyperthermia and hydroxyl radical (•OH) storm under 808 nm near‐infrared light illumination, enabling the damaging of extracellular polymeric substances (EPS) matrix to disperse biofilms and subsequently kill detached bacteria. Both in vitro and in vivo findings authenticate that biofilm infection monitoring‐and‐treating can be achieved. Moreover, the versatile Mn: C/G@MN patch is conducive to suppressing inflammatory responses, expediting collagen deposition, stimulating angiogenesis, and accelerating biofilm‐infected wound healing. As envisaged, this work highlights the potential of such a versatile platform for application in integrated theranostics for biofilm infection.