In Situ Redox-Omics Decoding of Nanoparticle–Protein Corona Interactions Drives the Mitochondrial Metabolic-Immunological Mechanism in Microglia

Nanoparticle-protein corona interactions critically determine biological responses but remain poorly characterized in living systems due to the lack of noninvasive analytical tools. In this study, we developed a redox-omics strategy that facilitated the in situ mapping of corona composition by tracking cysteine thiol oxidation markers induced by nanoparticles. As a research tool, we synthesized natural-organic-matter-derived carbon dots (nCDs) with dual superoxide dismutase/catalase-mimetic activity. A global redox-omics analysis identified 104 proteins that demonstrated significant redox reactions in response to treatment with nCDs. In particular, we found that nCDs specifically induced a conformational change in isocitrate dehydrogenase 1 (IDH1) by selectively reversing the oxidation of cysteine 269 (Cys²⁶⁹). In the mechanism, the site-specific reduction in cysteine 269 (Cys²⁶⁹) triggered a conformational switch of IDH1 that restored mitochondrial α-ketoglutarate flux and NADPH homeostasis, thereby blocking cytosolic mitochondrial DNA (mtDNA) leakage and subsequent cGAS-STING-driven neuroinflammation. Crucially, the nCDs-mediated metabolic checkpoint control inhibited the pro-inflammatory (M1) phenotypes of microglia, thereby achieving therapeutic efficacy in both zebrafish and murine ischemic stroke models, without inducing detectable toxicity. Collectively, we developed a label-free platform enabling in situ decoding of protein corona interactions via redox-sensitive cysteine profiling, eliminating the need for nanoparticle surface modifications.