Near-Infrared Light Photocatalysis Enables Synergistic Cancer Therapy

Area of Science:

• Biomedical Engineering
• Photochemistry
• Oncology

Background:

• Photocatalysis in living systems is limited by poor light penetration of UV/visible light into tissues.
• Developing photocatalysts that utilize near-infrared (NIR) light is crucial for deep-tissue therapeutic applications.

Purpose of the Study:

• To develop a novel NIR photocatalyst for enhanced cancer therapy.
• To investigate the dual-action mechanism of the photocatalyst involving reactive oxygen species generation and NADH oxidation.
• To evaluate the therapeutic efficacy of the photocatalyst in tumor treatment and immune activation.

Main Methods:

• Conjugation of a Pt(II) porphyrin with a cyanine dye to create an NIR photocatalyst.
• Utilizing 808 nm irradiation to activate the photocatalyst.
• Investigating dual energy/electron-transfer pathways for reactive oxygen species (ROS) generation (singlet oxygen, superoxide radical, hydroxyl radical) and NADH oxidation.
• Formulating the photocatalyst into biocompatible nanoparticles for delivery.
• Employing fluorescence (FL) and photoacoustic (PA) imaging for tumor delineation.
• Assessing the induction of immunogenic cell death and activation of tumor-specific cytotoxic T cells.

Main Results:

• The developed NIR photocatalyst effectively generates ROS and oxidizes NADH upon 808 nm irradiation.
• The dual action disrupts cellular redox balance, inducing immunogenic cell death.
• Biocompatible nanoparticles enabled precise tumor delineation via FL/PA imaging.
• The treatment activated tumor-specific cytotoxic T cells, inhibiting both primary and distant tumor growth.
• High therapeutic efficiency was achieved in impeding tumor progression.

Conclusions:

• This work establishes a novel NIR photocatalytic strategy for synergistic cancer therapy.
• The dual-action mechanism offers a promising approach for disrupting tumor redox balance and inducing an anti-tumor immune response.
• The developed system demonstrates potential for precise tumor imaging and effective treatment, highlighting its translational value.