NIR-Activable Charge Transfer Agents for Synergistic Photoimmunotherapy

Area of Science:

• Biomedical Engineering
• Materials Science
• Oncology

Background:

• Photothermal therapy (PTT) and photodynamic therapy (PDT) are promising cancer treatments.
• Designing effective photoimmunotheranostic agents that absorb near-infrared (NIR) light and activate the immune system is challenging.

Purpose of the Study:

• To develop a novel NIR-activable organic charge transfer complex (CTC) nanoparticle for synergistic photoimmunotherapy.
• To investigate the therapeutic efficacy of the nanoparticle in combination with immune checkpoint blockade.

Main Methods:

• Synthesized a CTC nanoparticle (PBND NP) using perylene (PER) and 4,5,9,10-tetrabromoisochromeno [6,5,4-def]isochromene-1,3,6,8-tetraone (Br4NDI).
• Evaluated NIR absorption, photothermal conversion efficiency, and reactive oxygen species (ROS) generation.
• Assessed the nanoparticle's ability to induce immunogenic cell death and combined its effects with programmed cell death protein 1 (PD-1) antibody treatment.

Main Results:

• PBND NP demonstrated excellent NIR absorption and a high photothermal conversion efficiency of 63.5%.
• NIR irradiation of PBND NP effectively generated ROS, leading to direct tumor ablation and suppression of distant tumor growth.
• The combination therapy significantly enhanced cancer treatment efficacy by blocking immune evasion.

Conclusions:

• The developed organic CTC nanoparticle is a potent platform for synergistic photoimmunotherapy.
• This approach offers a promising strategy for overcoming challenges in designing advanced cancer therapeutics.
• The study highlights the potential of organic CTCs in developing next-generation cancer treatments.