Oxygen vacancy regulation in an Ag-decorated CeO2 hollow multishelled structure for bacterial elimination and oxidative stress alleviation

Abstract

The synergistic effects of bacterial infection and oxidative stress remain critical barriers to tissue repair in chronic wounds. Although cerium oxide (CeO₂)-based nanozymes show promise, achieving a precise balance between their pro-oxidant and antioxidant activities is essential for therapeutic safety and efficacy. Herein, we report a multifunctional nanotherapy platform based on silver nanoparticle (AgNP)-decorated CeO₂ hollow multishelled structures (Ce HoMS/Ag). The hollow multishelled structure facilitates uniform AgNP dispersion and high active-site exposure. The Ag loading nonlinearly modulates the surface oxygen vacancies on CeO₂ HoMS, with the oxygen vacancy concentration decreasing initially and then increasing. This site-specific modification suppresses peroxidase-like activity, while the sustained release of Ag⁺ from Ce HoMS/Ag endows it with potent bactericidal activity against MRSA and E. coli. Moreover, the catalase- and superoxide dismutase-like activities of Ce HoMS/Ag enable effective scavenging of reactive oxygen species, thereby significantly accelerating wound closure and enhancing tissue regeneration in diabetic mouse wound models. This combination of defect engineering and hierarchical structure design provides an antibiotic-free strategy for simultaneous infection control and oxidative stress modulation in chronic wounds.