Selenium-Doped Carbon Dots Nanozymes Block Neuronal Pyroptosis through GPX4/ROS/NLRP3/GSDMD Axis to Attenuate Ischemic Stroke

Ischemia-reperfusion (I/R) injury is a critical contributor to adverse outcomes following stroke. During I/R injury, excessive production of reactive oxygen species (ROS) leads to various forms of neuronal cell death. Moreover, the blood-brain barrier (BBB) significantly hinders the delivery and efficacy of many neuroprotective agents. Given selenium’s crucial role in mitigating brain ischemia, we developed a selenium-based nanozyme encapsulated in glutathione (GSH)-conjugated liposomes to overcome these challenges. Specifically, we encapsulated selenium-doped carbon dot nanozymes (Se-CDs) within GSH-conjugated liposomes (Se-CD@LP-GSH) to enable targeted delivery and enhance therapeutic efficacy in ischemic stroke. This system demonstrates effective ROS scavenging capabilities both in vitro and in vivo, while also enhancing the biocompatibility of Se-CDs and their ability to cross the BBB. In the tMCAo model, Se-CD@LP-GSH reduces the neuronal death and infarct area following cerebral I/R injury, and promotes improvements in spatial learning ability and sensorimotor function. Mechanistically, Se-CD@LP-GSH promoted the upregulation of GPX4, an essential selenoprotein, thereby preserving mitochondrial function and suppressing ROS generation Consequently, the reduced ROS levels inhibit NLRP3/GSDMD-mediated neuronal pyroptosis during cerebral I/R injury. By improving the brain-targeting ability of Se-CDs via GSH-functionalized liposomal delivery, our work elucidates their neuroprotective efficacy and mechanistic basis, thus providing a translationally relevant strategy for ischemic stroke therapy.