Fe/Mo bimetallic oxide nanozyme achieves self-sufficient ROS cascade catalysis for cancer catalytic therapy

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Cancer Therapy

Background:

• Reactive oxygen species (ROS)-mediated catalytic therapy shows promise for cancer treatment.
• Current ROS systems often require external energy or substrates, limiting efficacy in the tumor microenvironment (TME).
• The heterogeneous TME presents challenges for conventional cancer therapies.

Purpose of the Study:

• To develop a self-sufficient nanozyme for enhanced cancer catalytic therapy.
• To investigate a nanozyme that utilizes endogenous TME components for ROS amplification.
• To establish a substrate self-sufficient ROS cascade for tumor treatment.

Main Methods:

• Fabrication of a Fe/Mo bimetallic oxide nanozyme supported by carbon nanospheres (Fe₂(MoO₄)₃/C).
• Evaluation of the nanozyme's superoxide dismutase (SOD)-like and peroxidase (POD)-like activities.
• Assessment of ROS generation and therapeutic effects in a 4T1 breast tumor model.

Main Results:

• The Fe₂(MoO₄)₃/C nanozyme demonstrated autonomous ROS cascade catalysis by converting endogenous superoxide anion to H₂O₂ and then to hydroxyl radicals.
• Enhanced catalytic kinetics and ROS amplification were observed compared to monometallic nanozymes.
• Significant tumor growth suppression and tumor cell apoptosis were achieved in vivo with favorable safety.

Conclusions:

• The Fe₂(MoO₄)₃/C nanozyme establishes a self-sufficient catalytic mechanism for continuous ROS amplification.
• This strategy offers a promising approach for precise and efficient tumor catalytic therapy.
• The nanozyme overcomes limitations of external stimulation and exogenous substrates in TME.