Engineering BN-Doped Open-Shell Polycyclic Hydrocarbons for Enhanced Photothermal Conversion and Therapy

Area of Science:

• Materials Science
• Chemistry
• Biomedical Engineering

Background:

• Traditional inorganic photothermal agents (PTAs) have poor biodegradability.
• Undoped carbon-based materials show low photothermal conversion efficiency (PCE).
• Existing organic PTAs often rely on donor-acceptor architectures.

Purpose of the Study:

• To develop a new class of stable, high-efficiency photothermal agents based on boron-and-nitrogen-doped polycyclic hydrocarbons (PHs).
• To engineer radicaloid character in PHs for enhanced photothermal therapy (PTT).

Main Methods:

• Synthesized atomically precise BN-doped polycyclic hydrocarbons with diradicaloid and tetraradicaloid character.
• Investigated synergistic integration of 1,2-BN units and radical engineering.
• Evaluated photothermal conversion efficiency (PCE) and stability of the synthesized compounds.
• Assessed in vitro cancer cell apoptosis under near-infrared (NIR) irradiation and in vivo tumor eradication in murine models.

Main Results:

• Developed stable BN-doped PHs with significant diradicaloid and tetraradicaloid character.
• Achieved exceptional ambient stability for tetraradicaloid species (half-lives > 1 year).
• Engineered BN-Dira exhibited high NIR absorption and a PCE of 83.6%.
• Demonstrated rapid cancer cell apoptosis in vitro and efficient tumor eradication in vivo with minimal side effects.

Conclusions:

• Established a new protocol for stable, radical-based PH PTAs.
• Provided a solution for high-performance cancer therapies using BN-doped PHs.
• Highlighted the potential for clinical translation of these novel photothermal agents.