What Are Gold NanoCages?

Gold nanocages refer to the hollow gold nanostructures with porous walls that were developed by Sun and Xia and Chen et al. in the early 2000s. The hollow and porous structures are synthesized by the galvanic replacement between silver nanocubes and chloroauric acid in aqueous solution. By controlling the size of nanocube templates, the monodispersed cubic nanocages are readily obtained with outer edge-length ranging from 30 to 200 nm. What are nanocages used for? The optical resonance of nanocages can be continuously tuned from visible to NIR region with narrow bandwidth as the galvanic reaction progresses. Owing to the strong optical absorption and scattering properties, the gold nanocages are a new class of gold-based multifunctional platforms for contrast enhancement of optical imaging, photothermal treatment of cancer, and on-demand drug delivery. Are gold nanocages different from gold nanoparticles? Gold nanocages are a novel class of plasmonic nanoparticles. Gold nanoparticles absorb light in the visible spectrum (about 550 nm), while gold nanocages absorb near-infrared light, with the least absorption by biological tissues. Gold nanocages can absorb light and heat, creating a photothermal effect that can kill cells. In fact, people use this effect to kill cancer cells. What are the differences between gold nanocages and nanorods? Gold nanocages and nanorods had very different light to heat transduction efficiencies, with gold nanocages requiring 18.4 times fewer particles and approximately half the gold mass of gold nanorods to achieve the same heating profile given a constant laser intensity. It was also observed in a study that while the photothermal macromolecular delivery enhancements were similar for the two systems when dosed by optical density, the tumoral uptake and biodistribution profiles for each of these shapes differed, with the nanocages residing in the liver, kidneys and spleen for less time than the nanorods. Additionally, it was observed that the nanocages were excreted from the body at a higher percentage of injected dose than the nanorods at both the 7 and 28 day time points. These findings have implications for the use of these constructs in diagnostic and therapeutic applications. About CD Bioparticles Offering the most comprehensive list of nanoparticles products with different sizes and surface properties, CD Bioparticles now provides a series of nanocages with hollow interiors and porous walls that can have strong near-infrared absorption (for photothermal effects) while maintaining a compact size. Our standard gold nanocages are citrate stabilized, and are suitable for applications such as targeting cancer cells, contrast enhancement agents, photothermal therapy, and biological immunoassay. Other ligands such as aromatics, carboxyls, amines are available upon request. References 1. Jingyi Chen, Chapter 18 – Noble Metal Nanoparticle Platform. (2014). Cancer theranostics. Academic Press. 2. Bhaskar, S., & Lim, S. (2017). Engineering protein nanocages as carriers for biomedical applications. NPG Asia Materials, 9(4), e371-e371. 3. Robinson, R., Gerlach, W., & Ghandehari, H. (2015). Comparative effect of gold nanorods and nanocages for prostate tumor hyperthermia. journal of Controlled Release, 220, 245-252. 4. Cobley, C. M., Au, L., Chen, J., & Xia, Y. (2010). Targeting gold nanocages to cancer cells for photothermal destruction and drug delivery. Expert opinion on drug delivery, 7(5), 577-587.