Self-Cascade Uricase/Catalase Mimics Alleviate Acute Gout

Uricase-based therapies are limited for gout partially due to the accumulation of H₂O₂ in an arthrosis environment with slow metabolism. To tackle this limitation, previous studies adopted a cascade reaction between the degradation of uric acid (UA) and timely elimination of H₂O₂ using complicated composites of uricase and catalase (CAT)/CAT-like nanozyme. Herein, the self-cascade nanozyme Pt/CeO₂ with high efficiency toward simultaneous UA degradation and H₂O₂ elimination is demonstrated on the basis of both uricase- and CAT-like activities in Pt, Ir, Rh, and Pd platinum-group metals. With an optimized molar ratio of Pt and CeO₂, Pt/CeO₂ (1/5) not only does better in degrading UA but also has excellent reactive oxygen species (ROS) and reactive nitrogen species (RNS) scavenging activities. In monosodium urate (MSU)-induced acute gout rats, Pt/CeO₂ nanozyme markedly alleviates pain along with joint edema, thus improving gait claudication and tissue inflammation. These results provide novel insights into strategies of an efficient enzyme-mimetic treatment for gout.