Bacteria-Triggered Multifunctional Hydrogel for Localized Chemodynamic and Low-Temperature Photothermal Sterilization

Pathogenic infections seriously threaten public health and have been considered as one of the most critical challenges in clinical therapy. Construction of a safe and efficient photothermal antibacterial platform is a promising strategy for treatment of bacterial infections. Considering that high temperature does harm to the normal tissues and cells, herein, a bacteria-triggered multifunctional hydrogel is constructed for low-temperature photothermal sterilization with high efficiency by integrating localized chemodynamic therapy (L-CDT). The hydrogel is constructed by incorporating copper sulfide nanoparticles (CuS_NPs ) with photothermal profile into the network of hyaluronic acid (HA) and Fe³⁺ -EDTA complexes, named as CHFH (CuS_NPs -HA-Fe³⁺ -EDTA hydrogel). Bacteria can be accumulated on the surface of CHFH, which secretes hyaluronidase to decompose the HA and release Fe³⁺ . The Fe³⁺ is reduced into Fe²⁺ in microenvironment of bacteria to trigger Fenton reaction. The generated hydroxyl radicals result in sterilization based on L-CDT within short range. By integrating with photothermal property of CuS_NPs , low-temperature photothermal therapy (LT-PTT) for sterilization is realized, which improves the antibacterial efficiency while minimizes damage to normal tissues. The CHFH is further used to prepare Band aid which effectively promotes the Staphylococcus aureus-infected wound healing process in vivo, confirming the great potential for clinical application.