Dual-Laser Strategy Revolutionizes Breast Cancer Photothermal Therapy

Breast cancer remains the most common cancer affecting women globally, and while photothermal therapy (PTT) offers a non-invasive, light-based treatment option, its clinical application has been limited by the risks of overheating healthy tissues and insufficient tumor destruction. Addressing these challenges, researchers have introduced a dual-laser photothermal therapy (DLPTT) strategy that enhances tumor ablation precision while reducing collateral tissue damage.

The DLPTT approach was developed by a research team from the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences (Beijing, China), along with collaborators. Their innovation focuses on the use of near-infrared photothermal agents with aggregation-induced emission (AIE) characteristics, which are designed to improve the safety and effectiveness of light-based breast cancer treatment. This two-stage strategy begins with a short burst of 808 nm laser irradiation for two minutes at approximately 50 °C, inducing DNA damage and suppressing the expression of heat shock protein HSP70—an action that counters tumor resistance. This is followed by a longer 13-minute treatment using a 1,064 nm laser at a lower temperature of 43 °C, which eliminates residual tumor cells with minimal inflammatory side effects. Supporting this precise targeting are second near-infrared (NIR-II) fluorescence imaging and photoacoustic imaging techniques, which allow for deeper tissue visualization and enhanced tumor localization through high signal-to-noise imaging.

In the study published in the PNAS, the method was validated in 4T1 breast cancer mouse models, where DLPTT led to significant tumor growth inhibition without any observable side effects. In vivo biosafety studies further showed that the treatment maintained stable body weight and resulted in minimal inflammatory cytokine release, indicating low systemic toxicity. By integrating advanced imaging technologies with a sequential heating mechanism, the DLPTT strategy not only addresses the limitations of traditional PTT but also opens new pathways for guided, safe, and effective breast cancer therapy. Its demonstrated efficacy and biosafety also support future applications in treating metastatic disease, especially when combined with immunotherapy.