Microenvironment Responsive Biomineralization Nanofirework Employing H₂S-Assisted Photothermal Therapy to Prompt Bacterial Wound Healing

Infected wounds present a complex challenge characterized by the dual problems of bacterial overgrowth and delayed healing. Conventional treatments have yet to address these issues concurrently and effectively. In response to this, we developed a nanofirework, ZnS/CuS@BSA (BSA, bovine serum albumin), synthesized via a biomineralization process. This nanocomposite is designed for hydrogen sulfide (H 2 S)-assisted photothermal therapy (PTT) targeting bacterial infections in wounds. Upon exposure to 808 nm laser irradiation, the CuS component of the ZnS/CuS@BSA nanofirework efficiently converts light energy into heat, which denatures the bacteria present in the wound. Simultaneously, the acidic environment at the wound site catalyzes the controlled release of H 2 S from the ZnS component. This released H 2 S not only inhibits bacterial peroxidase activity, which increases levels of reactive oxygen species (ROS), but also enhances cell migration and proliferation, accelerating the wound healing process. Furthermore, the concurrent release of zinc ions (Zn 2+ ) compromises the bacterial membrane integrity, enhancing the overall antibacterial efficacy of the nanocomposite. Both in vitro and in vivo studies have substantiated the capability of ZnS/CuS@BSA to significantly promote cell proliferation and inhibit bacterial growth, thereby facilitating rapid healing of the infected wound. This innovative approach, integrating H 2 S with PTT through a biomineralized nanofirework, offers a promising antibiotic-free strategy. It has the potential to significantly enhance the treatment of infected wounds, presenting a synergistic antimicrobial effect.