Polyvinylpyrrolidone-Coated Cubic Hollow Nanocages of PdPt₃ and PdIr₃ as Highly Efficient Self-Cascade Uricase/Peroxidase Mimics.

Abstract

Uricase-catalyzed uric acid (UA) degradation has been applied for hyperuricemia therapy, but this medication is limited by H₂O₂ accumulation, which can cause oxidative stress of cells, resulting in many other health issues. Herein, we report a robust cubic hollow nanocage (HNC) system based on polyvinylpyrrolidone-coated PdPt₃ and PdIr₃ to serve as highly efficient self-cascade uricase/peroxidase mimics to achieve the desired dual catalysis for both UA degradation and H₂O₂ elimination. These HNCs have hollow cubic shape with average wall thickness of 1.5 nm, providing desired synergy to enhance catalyst's activity and stability. Density functional theory calculations suggest the PdIr₃ HNC surface tend to promote OH*/O* desorption for better peroxidase-like catalysis, while the PdPt₃ HNC surface accelerates the UA oxidation by facilitating O₂-to-H₂O₂ conversion. The dual catalysis power demonstrated by these HNCs in cell studies suggests their great potential as a new type of nanozyme for treating hyperuricemia.