Polyvinylpyrrolidone-Coated Cubic Hollow Nanocages of PdPt 3 and PdIr 3 as Highly Efficient Self-Cascade Uricase/Peroxidase Mimics.

Uricase-catalyzed uric acid (UA) degradation has been applied for hyperuricemia therapy, but this medication is limited by H 2 O 2 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 PdPt 3 and PdIr 3 to serve as highly efficient self-cascade uricase/peroxidase mimics to achieve the desired dual catalysis for both UA degradation and H 2 O 2 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 PdIr 3 HNC surface tend to promote OH*/O* desorption for better peroxidase-like catalysis, while the PdPt 3 HNC surface accelerates the UA oxidation by facilitating O 2 -to-H 2 O 2 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.