Simultaneous Imaging and Selective Photothermal Therapy through Aptamer-Driven Au Nanosphere Clustering

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Photothermal Therapy

Background:

• Gold nanoparticles (Au NPs) exhibit tunable optical properties, making them promising for biomedical applications.
• Clustering of Au NPs can significantly alter their photothermal conversion efficiency, particularly in the near-infrared (NIR) spectrum.
• Understanding the mechanisms behind enhanced photothermal effects in Au NP clusters is crucial for optimizing their therapeutic potential.

Purpose of the Study:

• To investigate the photothermal properties of gold nanosphere clusters at the single-particle level.
• To elucidate the relationship between cluster formation and enhanced near-infrared (NIR) photothermal responses.
• To evaluate the efficacy of clustered Au NPs for dual-capability photothermal imaging and therapy of human prostate cancer cells.

Main Methods:

• Utilized photothermal heterodyne imaging (PTHI) microscopy for single-particle level analysis of Au nanosphere clusters.
• Quantified the increase in NIR photothermal response from monomers to dimers and trimers.
• Correlated photothermal enhancement with the longitudinal plasmon mode of clustered nanospheres.

Main Results:

• Significant enhancement of NIR photothermal responses observed with increasing cluster size (monomers to trimers).
• Averaged PTHI signal intensity increased approximately 10-fold for dimers and 25-fold for trimers compared to monomers.
• Clustered Au nanospheres demonstrated high efficiency and selectivity in dual-capability NIR photothermal imaging and therapy of prostate cancer cells.

Conclusions:

• The formation of Au nanosphere clusters dramatically enhances NIR photothermal effects, driven by their longitudinal plasmon mode.
• Clustered Au NPs offer a promising strategy for efficient and selective dual-capability photothermal imaging and therapy.
• This approach holds potential for simultaneous cancer imaging and therapy with precise 3D selectivity.