A near-infrared light responsive nanoheterojunction for antibacterial and anti-inflammatory applications through programmed ROS regulation

Reactive oxygen species (ROS) play a fundamental role in antibacterial therapeutic strategies. However, excessive ROS generation can disrupt redox homeostasis and induce a severe inflammatory response, causing immense stress on surrounding cells and tissues. Herein, an intelligent nanoheterojunction established with Prussian blue (PB) and manganese polyphthalocyanine (MnPPc), PB@MnPPc (PM), was established to achieve sequential antibacterial and anti-inflammatory functions via controllable ROS regulation. With spatiotemporal control of near-infrared (NIR, 808 nm) light, PM demonstrates the potential for on-demand generation and scavenging of ROS. When exposed to NIR irradiation, PM exhibits prominent bactericidal abilities, which result from its augmented singlet oxygen generation capacity and photothermal effects. These advantages originate from the narrow band gap as well as the enhanced electron-hole separation and transfer efficiency enabled by its unique heterostructure. Upon cessation of NIR irradiation, PM efficiently achieves ROS elimination and inflammation alleviation through its superior superoxide dismutase-like and catalase-like activities. In vivo studies in a mouse Staphylococcus aureus -infected skin wound model further confirmed the superior therapeutic effects of PM, which effectively eliminated bacteria, relieved inflammation, promoted collagen deposition, and angiogenesis. This work provides an attractive therapeutic modality for equipping nanoheterojunctions with antibacterial and anti-inflammatory properties through programmed ROS regulation.