A study carried out by researchers from POLYMAT-University of the Basque Country, INIFTA-Universidad Nacional de la Plata and the ALBA Synchrotron has made promising advances in the stabilization of gold nanoparticles (AuNPs) for use in cancer therapy. The work, published in the scientific journal Small, describes the synthesis of anisotropic hybrid particles of gold nanoparticles and nanogel, which overcome the challenges that have held back the clinical application of AuNPs, while maintaining their optical properties for the first time.
Gold nanoparticles are considered a powerful tool in photothermal cancer treatment due to their ability to convert light into heat, which is concentrated on tumor cells to destroy them. However, research has shown that unprotected anisotropic gold nanoparticles are prone to to undergo evaporation and condensation processes that result in the loss of their photothermal properties during the duration of the irradiation treatment. A new study, published in the scientific journal Small, presents a novel approach for stabilizing these particles while preserving their critical optical characteristics and, therefore, with the potential to improve the efficacy of cancer therapies.
Anisotropic gold nanoparticles are non-spherical photothermal particles that can be designed for thermal conversion by near-infrared irradiation, which is particularly advantageous in medical applications because of their high penetration depth in biological tissues and low toxicity to normal cells. However, their structural instability precludes prolonged therapeutic use. For this reason, previous studies have attempted to coat gold nanoparticles in gels such as polyethylene glycol (PEG). Yet, while these coatings improved stability, they also altered the unique shape and optical properties of the gold nanoparticles, significantly reducing their photothermal efficacy.
In this new study, researchers from POLYMAT-University of the Basque Country, INIFTA-La Plata National University, and the ALBA Synchrotron, devised a one-pot synthesis method that stabilizes anisotropic gold nanoparticles by coating them in an ultra thin, in situ polymeric nanogel. Using polyacrylamide (pAA) and poly-(N-isopropylacrylamide) (pNIPAM), the team achieved nanogel shells between 2–8 nanometers thick around each individual gold nanoparticle. This ultra thin coating preserved the nanoparticles’ dimensions and shape, ensuring that their unique optical and photothermal properties were unaffected. Notably, rod-shaped and star-shaped nanoparticles retained their structural integrity and optical characteristics, with rod-shaped hybrids showing particularly promising stability and efficiency for photothermal applications. The researchers also found that pNIPAM coatings offered the best protection for the nanoparticles, while pAA coatings exhibited optimal photothermal conversion efficiency.
Read more on ALBA website
