Near-infrared-IIb fluorescent nanozymes for imaging-guided treatment of traumatic brain injury

Traumatic brain injury (TBI) often results in damage to the blood–brain barrier (BBB), leading to secondary effects such as neuroinflammation mediated by reactive oxygen species (ROS), which can increase the risk of long-term neurological dysfunction. Therefore, it is crucial to remove excessive ROS and monitor the status of BBB for timely clinical intervention. Here, we developed a fluorescent nanozyme by doping Mn atoms into PbS/CdS quantum dots (QDs) that emit in the near-infrared-II (NIR-IIb, 1500–1700 nm) region, enabling imaging-guided treatment of TBI. The QD-based nanozyme exhibited excellent antioxidant activity due to uniformly distributed Mn atoms on the surface, which effectively scavenged ROS and inhibited the release of pro-inflammatory factors, thus providing neuroprotective effects for TBI treatment. Additionally, the nanozyme demonstrated exceptional NIR-IIb fluorescence performance, allowing for dynamic monitoring of BBB status with high spatiotemporal resolution to guide precise TBI treatment.