Layered double metal hydroxide nanosheets (LDH) delivery ICG for photoimmune antibacterial therapy and tissue infected wound regeneration

The management of persistent infection and immune dysregulation induced by methicillin-resistant Staphylococcus aureus (MRSA) strains in wound foci remains a significant challenge. These wounds often fail to heal properly due to chronic inflammation, which leads to immune dysregulation, and in severe cases, may even lead to amputation. Therefore, it is crucial to eliminate MRSA while simultaneously regulating immune homeostasis and promoting tissue regeneration for effective wound healing. Current treatment strategies primarily include antibiotics, negative pressure wound therapy, ultrasonic debridement, and growth factor therapy. However, insufficient immune regulation and high costs still limit their clinical translation and therapeutic efficacy. As an emerging and effective antibacterial therapy, photothermal therapy directly destroys bacterial structures through localized thermal effects. Herein, we have developed a layered double hydroxide nanosheet loaded with a photosensitizer (LDH@ICG@HA). This therapy has demonstrated significant antibacterial effects in vitro. In a mouse model of MRSA-infected skin wounds on the back, the therapy reduced the bacterial load at the wound site to 10.23% of the control group and effectively accelerated the wound healing process. Additionally, in the later stages of healing, a downregulation of inflammatory factors and macrophage polarization were observed. The results indicate that the LDH@ICG@HA treatment strategy not only possesses potent antibacterial capabilities but also effectively modulates immune responses during the healing process, promoting tissue regeneration and thereby significantly accelerating the healing of MRSA infections.