Tungsten-based polyoxometalate nanoclusters as ferroptosis inhibitors modulating S100A8/A9-mediated iron metabolism pathway for managing intracerebral haemorrhage

Intracerebral haemorrhage (ICH) is a devastating neurological disorder with high morbidity and mortality rates, largely owing to the lack of effective therapeutic strategies. Growing evidence has underscored the pivotal role of ferroptosis in intracerebral haemorrhage, and its contribution to neuronal death and exacerbation of brain injury, thus establishing it as a crucial target for therapeutic intervention. In recent years, polyoxometalate nanoclusters (NCs) have been applied in various neurodegenerative diseases, demonstrating neuroprotective effects. However, their impact on brain iron content and neurological function following ICH has yet to be reported. Here, we explored the potential of tungsten-based polyoxometalate (W-POM) NCs as ferroptosis inhibitors targeting the iron metabolic pathway mediated by S100A8/A9 for the treatment of ICH. We successfully synthesized ultra-small reduced W-POM NCs that can rapidly cross the blood-brain barrier and are cleared through the kidney. In vitro experiments demonstrated that W-POM NCs exhibit significant and stable ROS scavenging activity while effectively alleviating iron overload and associated neuronal damage. In vivo, W-POM NCs treatment restored iron metabolism homeostasis, suppressed neuroinflammation and oxidative stress, ultimately alleviating severe neurological damage and motor deficits in ICH mice. Proteomic combined with bioinformatic analyses identified two core genes, S100A8 and S100A9, most associated with W-POM NCs intervention in ICH. Further experiments confirmed that W-POM NCs act by modulating the toll-like receptor 4/hepcidin/ferroportin signaling pathway, thereby regulating iron metabolism and reducing secondary brain injury. This study pioneers the application of polyoxometalates in intracerebral haemorrhage, offering a novel and promising therapeutic approach for the management of ferroptosis-related brain injuries.