An enzyme-mimicking reactive oxygen species scavenger targeting oxidative stress-inflammation cycle ameliorates IR-AKI by inhibiting pyruvate dehydrogenase kinase 4

<b>Rationale</b>: Ischemia-reperfusion-induced acute kidney injury (IR-AKI), characterized by the abrupt decline in renal function, is distinguished by the intricate interplay between oxidative stress and inflammation. In this study, a reactive oxygen species (ROS) scavenger-CF@PDA was developed to effectively target antioxidant and anti-inflammatory pathways to disrupt the oxidative stress-inflammation cycle in IR-AKI. <b>Methods</b>: UV-vis absorption spectra, FTIR spectra, and TEM were employed to determine the successful construction of CF@P. ABTS, TMB, and NBT analyses were performed to detect the antioxidant ability and enzyme-mimicking ability of CF@P. <i>In vitro</i> and <i>in vitro</i>, the antioxidant/anti-inflammatory effect of CF@P was detected by MTT, qPCR, fluorescence, and flow cytometry. Multi-omics revealed the mechanism of CF@P in IR-AKI therapy, and molecular docking was further used to determine the mechanism. MRI and photoacoustic imaging were employed to explore the dual-mode imaging capacity of CF@P in IR-AKI management. <b>Results</b>: CF@P could disrupt the oxidative stress-inflammatory cascade by scavenging ROS, reducing pro-inflammatory cytokines, and modulation of macrophage polarization. Subsequent multi-omics indicated that the renal protective effects may be attributed to the inhibition of pyruvate dehydrogenase kinase 4 (PDK4). Metabolomics demonstrated that CF@P could improve the production of antioxidant compounds and reduce nephrotoxicity. Additionally, CF@P exhibited promising capabilities in T1-MRI and photoacoustic imaging for AKI management. <b>Conclusions</b>: Collectively, CF@P, possessing antioxidant/anti-inflammatory properties by inhibiting PDK4, as well as imaging capabilities and superior biocompatibility, holds promise as a therapeutic strategy for IR-AKI.