Nanosheet-shaped WS2/ICG nanocomposite for photodynamic/ photothermal synergistic bacterial clearance and cutaneous regeneration on infectious wounds

Bacterial infections present a significant threat to human health, a challenge that is intensified by the slow pace of novel antibiotic development and the swift emergence of bacterial resistance. The development of novel antibacterial agents is crucial. Indocyanine green (ICG), a widely used imaging dye, efficiently generates reactive oxygen species (ROS) and heat for treating bacterial infections but suffers from aggregation and instability, limiting its efficacy. In this study, tungsten disulfide (WS2) nanosheet with a high surface area was used to load ICG, creating a multifunctional nanocomposite, WS2/ICG, aimed at treating bacteria-infected wounds. The two-dimensional surface structure of WS2 provides dispersible binding sites for ICG, and the synthesized nanocomposite exhibits excellent stability. Under near-infrared (NIR) laser excitation, the generated heat further synergistically enhances the yield of singlet oxygen. Additionally, the WS2/ICG nanoplatform synergistically combines photothermal effect with photodynamic effect, achieving a "1 + 1 > 2" enhancement. Upon NIR laser excitation, the nanocomposite disrupts bacterial cell membranes through localized heating and ROS accumulation, leading to energy metabolism system disruption and subsequent bacterial lysis and death. The findings demonstrate WS2/ICG's outstanding antibacterial properties and biocompatibility, effectively treating skin infections and promoting tissue regeneration, providing a simple and promising solution for bacteria-infected wounds.