Aza-BODIPY nanoparticles for near-infrared triggered synergistic photothermal and photodynamic antibacterial therapy

Wound healing is a complicated process that can be susceptible toward infection caused by bacteria. The surging drug resistance has become one of the biggest challenges to the treatment of these infections in public health. Herein, a new asymmetrical aza-boron-dipyrromethene (ABDP) probe is prepared and encapsulated with cholesterol-modified polyethylene glycol polymer (Chol-PEG 2000 -NH 2 ) to construct a PTT/PDT dual-modality antibacterial agent (the ABDP NPs) and provide a new material for the treatment of MRSA-based infections. The ABDP NPs show remarkable wide UV–Vis absorption at 300–850 nm and superior bactericidal effects against Staphylococcus aureus ( S. aureus ), Escherichia coli ( E. coli ), and Methicillin-resistant S. aureus (MRSA), which can be controlled by a phototheranostic antibacterial switch (808 nm laser). Histological analysis indicates that wounds treated by the ABDP NPs plus NIR laser irradiation exhibit more complete re-epithelialization, abundant collagen fibers, and higher hair follicle numbers than the vancomycin-treated group. This study provides a promising perspective using aza-BODIPY dye for the treatment of multidrug-resistant bacteria-based infections and clinical applications in the future.