Myocardium-Targeted Near Infrared-IIb Emitting Atomically Dispersed Catalysts for ROS Scavenging in Acute Myocardial Infarction.

Acute myocardial infarction (AMI) involves ischemia-driven cardiomyocyte necrosis accompanied by excessive reactive oxygen species (ROS) and innate immune activation. While reperfusion restores blood flow, it does not mitigate oxidative stress and inflammation that worsen injury, and conventional anti-inflammatories risk systemic immunosuppression. Here, we developed manganese-doped Ag2Te quantum dots (Mn: Ag2Te QDs) surface-modified with tannic acid (TA) to achieve myocardial-targeted therapy, real-time visualization of drug distribution, and post-treatment verification. Mn doping endows enzyme-mimetic antioxidant activity, enabling efficient scavenging of ROS to alleviate oxidative stress and dampen inflammatory signaling, including cGAS-STING- and ZBP1-associated pathways. TA confers strong cardiac affinity, enhancing selective accumulation in infarcted myocardium. The QDs emit in the NIR-IIb window, allowing deep-tissue, high-contrast, real-time fluorescence imaging for noninvasive monitoring of biodistribution and targeted delivery. In vitro and in vivo studies demonstrate robust ROS clearance, reduced inflammation, and improved cardiac function, with favorable biocompatibility and safety. This integrated platform unites myocardial targeting, ROS scavenging, and NIR-IIb imaging, offering a promising approach for the precision treatment of AMI.