Interfacial electronic regulation in α-FeOOH@Ag nanocomposites enables ROS-enhanced antibacterial activity and MRSA-infected wound healing

The rapid spread of bacterial resistance represents a significant global health challenge. Silver nanoparticles (Ag NPs) demonstrate potent antibacterial activity, but they tend to aggregate and release Ag⁺ rapidly, leading to cytotoxicity and limiting their clinical applicability. Here, sea-urchin-shaped α-FeOOH (αF) synthesized via a solvothermal method serves as a carrier for ∼5 nm Ag NPs, yielding α-FeOOH@Ag (αFA) nanocomposites. A dual "carrier-confinement interface anchoring" mechanism ensures stable Ag dispersion and markedly increases the electronic-state density near the Fermi level at the αF interface. This enriched electronic state facilitates interfacial charge transfer, promoting the spontaneous formation of reactive oxygen species (ROS). Consequently, these features confer pronounced antibacterial activity on the nanocomposite. The antibacterial effects originate from Ag⁺ release and αF-catalyzed ROS generation, which disrupt bacterial membranes, induce ion leakage, and trigger oxidative damage, thereby mitigating resistance development. In an MRSA-infected rat wound model, αFA significantly reduces bacterial load, disrupts biofilms, alleviates inflammation, and promotes epithelialization and collagen deposition. This highly dispersed, low-silver-loading, controlled-release, ROS/Ag⁺-synergistic strategy provides an efficient, low-toxicity, and long-lasting antibacterial platform.