Search

Chemodynamic therapy (CDT) has great potential in cancer treatment, but its efficacy is limited due to non‐specificity, insufficient hydrogen peroxide (H2O2), and excessive glutathione (GSH) within the tumor microenvironment (TME). Here, an intelligent nanoplatform (Fe3O4@MnO2@NO@Au NPs, abbreviated as CD44FMNA) is reported for the treatment of breast cancer, which is constructed with Fe3O4 nanoparticles (NPs) as the core coated with manganese dioxide (MnO2) nanoshells encapsulating NO donors and gold nanoparticles (Au NPs) within the pores of MnO2, followed by the conjugation of targeting ligand anti‐CD44 mAb. The fabricated CD44FMNA initially remains inactive in normal cells, but after CD44 receptor ‐mediated MDA‐MB‐231 cell‐specific endocytosis, acidic TME can induce the decomposition of the MnO2 shell to release NO donors, thereby dually depleting the existing GSH in cells and enhancing the Fenton‐like reaction in a cascade manner. The generation of hydroxyl radicals (·OH) and the dual depletion of GSH can significantly weaken the GSH‐related antioxidant defense system (ADS) within MDA‐MB‐231 cells, accelerating apoptosis and cell death via the mitochondrial pathway. In addition, in vivo studies demonstrate that CD44FMNA can effectively inhibit tumor growth with good biosafety. Therefore, this nanoplatform may provide an effective therapy for the treatment of breast cancer. [ABSTRACT FROM AUTHOR]

Bacterial wound infections are a serious threat due to the emergence of antibiotic resistance. Herein, we report an innovative hybrid nanozyme independent of antibiotics for antimicrobial wound healing. The hybrid nanozymes are fabricated from ultra-small Au NPs via in-situ growth on metal-organic framework (MOF)-stabilised Fe3O4 NPs (Fe3O4@MOF@Au NPs, FMA NPs). The fabricated hybrid nanozymes displayed synergistic peroxidase (POD)-like activities. It showed a remarkable level of hydroxyl radicals (·OH) in the presence of a low dose of H2O2 (0.97 mM). Further, the hybrid FMA nanozymes exhibited excellent biocompatibility and favourable antibacterial effects against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. The animal experiments indicated that the hybrid nanozymes promoted wound repair with adequate biosafety. Thus, the well-designed hybrid nanozymes represent a potential strategy for healing bacterial wound infections, without any toxic side effects, suggesting possible applications in antimicrobial therapy. [ABSTRACT FROM AUTHOR]