Gold Nanodots-Anchored Cobalt Ferrite Nanoflowers as Versatile Tumor Microenvironment Modulators for Reinforced Redox Dyshomeostasis.

Abstract

Given that tumor microenvironment (TME) exerts adverse impact on the therapeutic response and clinical outcome, robust TME modulators may significantly improve the curative effect and increase survival benefits of cancer patients. Here, Au nanodots-anchored CoFe₂O₄ nanoflowers with PEGylation (CFAP) are developed to respond to TME cues, aiming to exacerbate redox dyshomeostasis for efficacious antineoplastic therapy under ultrasound (US) irradiation. After uptake by tumor cells, CFAP with glucose oxidase (GOx)-like activity can facilitate glucose depletion and promote the production of H₂O₂. Multivalent elements of Co(II)/Co(III) and Fe(II)/Fe(III) in CFAP display strong Fenton-like activity for·OH production from H₂O₂. On the other hand, energy band structure CFAP is superior for US-actuated ¹O₂ generation, relying on the enhanced separation and retarded recombination of e^-/h⁺ pairs. In addition, catalase-mimic CFAP can react with cytosolic H₂O₂ to generate molecular oxygen, which may increase the product yields from O₂-consuming reactions, such as glucose oxidation and sonosensitization processes. Besides the massive production of reactive oxygen species, CFAP is also capable of exhausting glutathione to devastate intracellular redox balance. Severe immunogenic cell death and effective inhibition of solid tumor by CFAP demonstrates the clinical potency of such heterogeneous structure and may inspire more relevant designs for disease therapy.