Computed Tomography Imaging Guided Microenvironment-Responsive Ir@WO_3-x Dual-Catalytic Nanoreactor for Selective...

Area of Science:

• Biomedical Engineering
• Materials Science
• Oncology

Background:

• Radiotherapy (RT) faces challenges including tumor hypoxia, damage to healthy tissues, and inaccurate guidance, often leading to treatment failure.
• Developing multifunctional platforms is crucial for overcoming these limitations and improving precision radiosensitization.

Purpose of the Study:

• To develop a multifunctional therapeutic platform, Ir@WO_3-x, to address critical issues in RT for enhanced precision radiosensitization.
• To investigate the combined effects of radiosensitization, hypoxia amelioration, and computed tomography (CT) imaging using the novel nanoreactor.

Main Methods:

• Fabrication of Ir@WO_3-x nanoreactors with integrated Ir enzyme-mimic nanocrystals.
• Evaluation of X-ray absorption for radiosensitization.
• Assessment of H₂O₂ to O₂ conversion under near infrared-II (NIR-II) light for hypoxia mitigation.
• Analysis of peroxidase-like activity for reactive oxygen species (ROS) generation.
• Utilizing the material as a CT contrast agent for tumor imaging.

Main Results:

• Ir@WO_3-x demonstrated strong X-ray absorption, acting as an effective radiosensitizer.
• The nanoreactor catalyzed H₂O₂ to O₂, alleviating tumor hypoxia and inhibiting HIF-1α expression, thereby enhancing RT-induced DNA damage.
• Peroxidase-like activity of Ir@WO_3-x boosted ROS levels, increasing oxidative damage and promoting ROS-dependent cell death.
• The material exhibited high X-ray attenuation, providing excellent tumor-tissue contrast for CT imaging.

Conclusions:

• The Ir@WO_3-x nanoreactor platform effectively addresses key challenges in RT, including hypoxia and imaging guidance.
• This multifunctional approach significantly enhances RT efficiency and offers potential for improved precision cancer therapy through advanced materials.