Palladium Nanocapsules for Photothermal Therapy in the Near-Infrared II Biological Window

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Plasmonic photothermal therapy (PPTT) shows promise for cancer treatment but faces limitations.
• Current PPTT methods struggle with low light penetration and high laser power requirements.
• Existing nanostructures often have limited efficacy in the near-infrared-I (NIR-I) region.

Purpose of the Study:

• To develop advanced nanomaterials for effective PPTT overcoming current limitations.
• To engineer bimetallic palladium nanocapsules (Pd Ncap) with dual NIR-I and NIR-II optical responses.
• To evaluate the efficacy and biocompatibility of Pd Ncap for targeted cancer therapy.

Main Methods:

• Synthesized bimetallic palladium nanocapsules (Pd Ncap) with gold cores and perforated palladium shells.
• Investigated photothermal properties, including photothermal conversion efficiency at NIR-II wavelengths.
• Surface-functionalized nanocapsules with Herceptin (Pd Ncap-Her) for targeted delivery to SK-BR-3 breast cancer cells.
• Performed in vitro and in vivo studies to assess cell death, tumor ablation, and biocompatibility.

Main Results:

• Pd Ncap exhibited high photothermal stability and conversion efficiency (~49%) in the NIR-II region (1064 nm) at low laser power density (0.5 W/cm²).
• Pd Ncap-Her achieved over 98% cancer cell death in vitro at low concentrations (50 μg/mL) and laser power.
• Demonstrated effective in vivo tumor ablation in mice with excellent biocompatibility and reactive oxygen species (ROS) scavenging ability.

Conclusions:

• Bimetallic palladium nanocapsules (Pd Ncap) are highly effective phototherapeutic agents for cancer treatment.
• The developed nanostructures overcome limitations of traditional PPTT, enabling low-power, high-efficiency therapy.
• Pd Ncap offers a promising ROS-protecting therapeutic strategy with potential for broad clinical application in oncology.