Synthesis of Ultrasmall Single-Crystal Gold–Silver Alloy Nanotriangles and Their Application in Photothermal Therapy

Abstract

Photothermal therapy has always been a very attractive anti-cancer strategy, drawing a lot of attention thanks to its excellent performance as a non-invasive and pretty safe technique. Lately, nanostructures have become the main characters of the play of cancer therapy due to their ability to absorb near-infrared radiation and efficient light-to-heat conversion. Here we present the synthesis of polyethylene glycol (PEG)-stabilized hybrid ultrasmall (<20 nm) gold–silver nanotriangles (AuAgNTrs) and their application in photothermal therapy. The obtained AuAgNTrs were deeply investigated using high-resolution transmission electron microscopy (HR-TEM). The cell viability assay was performed on U-87 glioblastoma multiforme cell model. Excellent photothermal performance of AuAgNTrs upon irradiation with NIR laser was demonstrated in suspension and in vitro, with >80% cell viability decrease already after 10 min laser irradiation with a laser power P = 3W/cm2 that was proved to be harmless to the control cells. Moreover, a previous cell viability test had shown that the nanoparticles themselves were reasonably biocompatible: without irradiation cell viability remained high. Herein, we show that our hybrid AuAgNTrs exhibit very exciting potential as nanostructures for hyperthermia cancer therapy, mostly due to their easy synthesis protocol, excellent cell compatibility and promising photothermal features.

Optimized Biocompatible Gold Nanotriangles with NIR Absorption for Photothermal Applications

“…Only a slight decrease in lysosomal activity (evaluated with NR assay) at 100 μg/mL was found, non-correlated with mitochondrial affection. According to the bibliography, these Au NTs are among those with the highest cyto-tolerance. , …”

“…According to the bibliography, these Au NTs are among those with the highest cyto-tolerance. 63,64 Photothermal Efficiency of Au NTs. Dispersions of plasmonic Au NPs can absorb energy from light and convert it efficiently into heat, which can be exploited for photothermal therapies.…”

Near-Infrared Fluorescent Hydroxyapatite Nanoparticles for Targeted Photothermal Cancer Therapy

“…Since PTT is a non-chemotherapeutic tumor treatment, it is considered relatively safe compared with the risk of anticancer drugs from the chemotherapy. In order to better apply the PTT strategy, various types of PTT agents have been extensively developed depending on the nanosized materials, including noble metal-, carbon-, and synthetic organic polymer-based nanoparticles [ 4 , 5 , 6 , 7 , 8 , 9 ]. PTT agents should have strong absorption in the traditional near-infrared (NIR) region (650–950 nm) for efficiently converting light energy into thermal energy to induce hyperthermia, leading to cancer cell death [ 10 , 11 , 12 , 13 , 14 , 15 , 16 ].…”

Usage of Nanoparticles to Alter Neutrophils’ Function for Therapy

“…The emergence of nanotechnology has brought new hope. In recent years, a few nanomaterials have been designed in research, such as biomedical science − and photothermal therapy. − Nanomaterials can alleviate drug elimination to a certain extent and accumulate at the tumor site due to the enhanced permeability and retention (EPR) effect. ,− The accumulation capability will be even more improved if a targeting group is attached . However, it is still difficult for nanomaterials to carry drugs through the vascular barrier .…”