Multifunctional nanozyme therapy accelerates hematoma clearance and attenuates genome damage and senescence after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating form of stroke characterized by rapid hematoma formation in the brain, resulting in multiple pathological events due to mass effect and toxicity of extravasated blood and its blood products. ICH leads to poor long-term outcomes despite advances in hematoma management, largely due to secondary injury mechanisms. Hemin and iron released in the peri-hematomal environment trigger genome damage, transient senescence, and inflammatory signaling that may initially limit ferroptosis but ultimately contribute to persistent neurodegeneration. Given the multiple pathological events initiated following ICH, it is not surprising that no single neuroprotective strategy has been effective. In this study, we investigated these interconnected pathways in a rodent model of ICH and evaluated the therapeutic potential of DEF-OAC-PEG, a pleiotropic synthetic oxidized carbon nano-enzyme that has catalytic mitochondrial and cellular protective actions, covalently bonded to the iron chelator deferoxamine and shown in our previous work to have strong <i>in vitro</i> protective effects against hemin and iron toxicity and <i>in vivo</i> evidence of reduction in genome damage. Here, we examined mechanisms of action in an <i>in vivo</i> ICH mouse model. Autologous whole blood injection into the mouse brain striatum induced robust astroglial and microglial activation, increased neuronal Heme Ooxygenase-1 expression, and DNA damage and senescence in neurons and oligodendrocytes. Systemic intraperitoneal administration of DEF-OAC-PEG, initiated 3 hours after ICH, resulted in robust brain penetration in wild-type mice, with preferential accumulation in peri-hematomal regions of ICH mice. Surprisingly, nanozyme treatment produced a rapid, significant acceleration of hematoma clearance compared with untreated ICH animals. This effect was associated with enhanced detection of CD68-positive microglia/macrophages, which also showed internalized nanozymes, suggesting that nanozyme promotes immune-mediated hematoma resolution. Importantly, DEF-OAC-PEG also markedly attenuated ICH-induced DNA damage and senescence in neurons and oligodendrocytes. Together, these findings identify genome instability and senescence as key consequences of hemorrhagic brain injury and demonstrate that multifunctional nanozyme therapy can simultaneously promote hematoma resolution and mitigate secondary neurodegenerative injury following ICH.