NIR-Responsive Nanoplatform Based on CuO₂ with Self-Supplied H₂O₂/O₂ for Synergistic Photodynamic-Chemodynamic-Photothermal Therapy of Skin Abscesses

Chemodynamic therapy (CDT) and photodynamic therapy (PDT) have emerged as promising strategies for treating skin abscesses. However, their therapeutic efficacy is fundamentally constrained by the hypoxic and hydrogen peroxide-deficient microenvironment characteristic of abscesses. Herein, we developed a near-infrared (NIR) light-responsive nanoplatform (ICG/CuO 2 @PCM) by encapsulating copper peroxide (CuO 2 ) and indocyanine green (ICG) within a phase-change material (PCM), which enables control over self-supplied H 2 O 2 /O 2 release via an NIR-triggered cascade. Upon irradiation, ICG-mediated photothermal conversion elevates the temperature beyond the PCM melting threshold, triggering a burst release of CuO 2 and ICG. CuO 2 generates hydroxyl radicals (•OH) through a Fenton-like reaction in the acidic wound microenvironment. Additionally, CuO 2 can thermally decompose under photothermal conditions to produce a sustained oxygen supply, which ICG immediately converts into singlet oxygen ( 1 O 2 ), thereby enhancing PDT efficiency. Furthermore, photothermal therapy not only enhances the efficiency of CDT but also provides additional antibacterial support. Remarkably, ICG/CuO 2 @PCM (NPs), coupled with irradiation, accelerate abscess wound recovery by dispersing biofilm, killing bacteria, and promoting macrophage polarization toward an anti-inflammatory phenotype. Overall, this NIR-responsive nanoplatform highlights the promise in controlled modulation of microenvironment-adaptive antimicrobial strategies to overcome current limitations of hypoxic infections.