Development of D–A–D‐Type NIR‐II Photothermal Agents for Synergistic Eradication of Multidrug‐Resistant Bacteria and Promoting Diabetic Wound Healing

Abstract The challenge in treating diabetic foot infections caused by drug‐resistant bacteria is rapidly eradicating bacteria and accelerating wound healing. NIR‐II‐induced photothermal therapy (PTT) offers notable advantages over conventional treatments, such as broad‐spectrum bactericidal efficacy, better penetration depth in biological tissues, and higher skin tolerance thresholds, making it particularly suitable for addressing diabetic foot infections. Herein, it is found that NIR‐II dye IR26 exhibited good photothermal effects but poor photothermal stability. By modifying IR26 with methoxy and triphenylamine groups, a novel D–A–D‐type NIR‐II small molecule photothermal agent (IRC) is developed, with high photothermal stability and photothermal conversion efficiency (44.3%). IRC exhibited a maximum absorption wavelength of 1166 nm and a maximum emission wavelength of 1238 nm. However, PTT alone cannot effectively promote diabetic wound healing. Therefore, a novel nanoplatforms (Cur‐IRC@PCM) are developed by coloading IRC and curcumin, a natural wound–healing compound, into thermosensitive liposomes to treat MRSA‐infected diabetic wounds. Under 980 nm laser irradiation, Cur‐IRC@PCM provided PTT and controlled the precise release of curcumin, effectively synergizing to eradicate drug‐resistant bacteria and accelerate wound closure. The intelligent antibacterial nanoplatforms Cur‐IRC@PCM also exhibits excellent biocompatibility, rendering it a promising therapeutic tool in biomedical fields for combating drug‐resistant bacterial infections.