NIR-Activated Bactericidal-Antioxidative Microneedles Based on Organic J-Aggregates to Accelerate Infected Wound Healing

It is imperative to provide timely and effective treatment for bacterially infected wounds to prevent progression to more severe pathological conditions. Herein, we report a near-infrared (NIR)-activated nanoassembly (BC@P) integrating dual functions of bactericidal activity and tissue repair. The nanoassembly is facilely fabricated via the self-assembly of organic photothermal molecules B(TIBC)₂, natural antioxidant molecules curcumin, and biocompatible eight-arm polyethylene glycol (8-arm-PEG). B(TIBC)₂ is rationally designed with an acceptor-donor-acceptor (A-D-A) structure and tailored photothermal activity; moreover, it undergoes assembly induced J-aggregation, leading to a red-shifted absorption tail extending into the NIR-II region. Consequently, BC@P exhibits broadened NIR absorption, favorable photothermal conversion efficiency (53.1%), efficient NIR-II emission, and robust antioxidative capacity. When integrated into a hyaluronic acid-based microneedle (MN) patch, BC@P efficiently penetrates the skin barrier to eradicate wound-resident bacteria, modulate the inflammatory response, and accelerate the healing of bacterial-infected wounds with excellent biosafety. This work not only presents a promising "kill-and-repair" platform for infected wound therapy but also provides a guiding paradigm for the design of J-aggregate scaffolds in biological NIR-II imaging applications.