Au Nanomatryoshkas as Efficient Near-Infrared Photothermal Transducers for Cancer Treatment: Benchmarking against Nanoshells

Abstract

Au nanoparticles with plasmon resonances in the near-infrared (NIR) region of the spectrum efficiently convert light into heat, a property useful for the photothermal ablation of cancerous tumors subsequent to nanoparticle uptake at the tumor site. A critical aspect of this process is nanoparticle size, which influences both tumor uptake and photothermal efficiency. Here, we report a direct comparative study of ∼90 nm diameter Au nanomatryoshkas (Au/SiO2/Au) and ∼150 nm diameter Au nanoshells for photothermal therapeutic efficacy in highly aggressive triple negative breast cancer (TNBC) tumors in mice. Au nanomatryoshkas are strong light absorbers with 77% absorption efficiency, while the nanoshells are weaker absorbers with only 15% absorption efficiency. After an intravenous injection of Au nanomatryoshkas followed by a single NIR laser dose of 2 W/cm2 for 5 min, 83% of the TNBC tumor-bearing mice appeared healthy and tumor free >60 days later, while only 33% of mice treated with nanoshells survived the same period. The smaller size and larger absorption cross section of Au nanomatryoshkas combine to make this nanoparticle more effective than Au nanoshells for photothermal cancer therapy.

Nanoparticles Heat through Light Localization

“…(34,35) A detailed explanation of the synthesis of the gold nanomatryoshkas can also be found in recent literature. (28,29) …”

Near-infrared remotely triggered drug-release strategies for cancer treatment

“…One promising approach in cancer treatment is the use of gold-based nanostructures, whose strong optical absorption is due to their plasmon resonance, to provide safe and effective light-based therapeutics. Plasmonic nanostructures are advantageous due to their unique optical properties, low toxicity, in vivo stability, and enhanced tumor uptake (4)(5)(6)(7)(8)(9)(10). One approach uses near-infrared (IR) light to heat silica core-gold shell nanoshells (NS) photothermally to locally ablate tumors, which has been shown to lead to tumor remission in mice at rates above 90% (11)(12)(13).…”

Controllable Cobalt Oxide/Au Hierarchically Nanostructured Electrode for Nonenzymatic Glucose Sensing

“…In general, solid structures have higher scattering efficiencies than hollow ones which means that there is less energy available to convert into heat in photothermal applications [15,29,158,213,214]. For example, it has been reported that silica-gold core-shell nanoparticles (150 nm diameter) had total extinctions that are comprised of only 15% absorption efficiency [215]. Shells also have broadened spectral line widths due to variation in size and shape within an ensemble and are considered cytotoxic due to the polymer core [190,216].…”