Curcumin-functionalized Prussian blue for NIR-II photothermal antibacterial therapy

FDA-approved Prussian blue (PB) has been developed as a nano photothermal therapy (PTT) agent due to its unique Fe^III-CN-Fe^II structure and the resulting near-infrared (NIR) absorption performance. Nevertheless, the NIR absorption peaks of traditional PB-based nanomedicines are often located in the NIR-I region (700-900 nm) rather than NIR-II region (900-1700 nm), thus limiting their efficacy in treating deep lesions. Herein, curcumin (Cur)-functionalized PB nanomedicine is elaborately designed for NIR-II PTT against bacterial infections. In addition to serving as a dispersant and a reducing agent, the introduced Cur effectively regulates the absorption peak of PB to the NIR-II region. Moreover, as-prepared Cur-functionalized PB nanomedicine demonstrated superior photothermal antibacterial performance against S. aureus. Therefore, this study proffers a new attempt centered on the optical performance regulation of PB and lays the foundation for next-generation PTT nanomedicines.