Posted: October 16, 2008

New Manufacturing Method Results in Non-Cytotoxic Nanorods for In-Vivo Therapeutics, Imaging, and Diagnostics

(Nanowerk News) A revolutionary new gold nanorod manufacturing method has been developed at Nanopartz where their patent pending gold nanorods are proving their ability to be the future in-vivo nanoparticle for the detection and treatment of solid tumor cancers without the need for surgery.
This new proprietary method, removes the cytotoxic cetyl trimethylammonium bromide (CTAB) capping agent necessary for manufacturing, replacing it with polyethylene glycol (PEG). PEG has a low toxicity and is used in a variety of products. It is the basis of a number of laxatives and skin creams and many other well known products. The combination of the gold nanorods with PEG coatings, name Ntracker, has shown shown half-life circulation times of greater than 17 hours in mice. For years researchers have known of the advantages offered by gold nanorods for in-vivo and in-vitro applications. Gold nanorods have unprecedented photothermal absorption characteristics. That is, they efficiently convert light to heat. In addition, gold nanorods are very good light scatterers. These two properties, light scattering and photothermal absorption, are the two properties necessary for successful in-vivo therapeutics, imaging, and diagnostics.
But until now, the limitation on commercializing gold nanorods for in-vivo and in-vitro applications has been toxicity. Nanopartz has now solved this problem with the release of their Ntracker nanorods.
gold nanorods for in vivo imaging
In solid tumor cancer therapy, the gold nanorods can be functionalized with coatings that are specific or even non-directional for solid tumor cancers. Once injected, the nanorods circulate throughout the body, and over time, concentrate in the targeted solid tumor cancer. The nanorods, manufactured to absorb at specific near-infrared wavelengths, readily convert near-infrared light to heat. Since human skin and tissue is fairly transmissive to near-infrared light, a low power near-infrared laser may be used outside the body to heat the solid tumor to temperatures that destroy the tumor cells, not affecting healthy tissue adjacent to the tumor - all without the need for surgery.
As a contrast enhancement agent, gold nanorods may be manufactured to scatter at discrete wavelengths anywhere in the near-infrared. This property lends itself to the ability to enhance detection of solid tumor cancer that might normally be missed using conventional techniques. Currently, researchers are using nanorods as a contrast enhancement for Photoacoustic Imaging, Optical Coherence Tomography, as well as Surface Enhanced Raman Scattering.
Other potential applications of gold nanorods include the use to improve the efficiency of solar cells, for use in negative refractive index materials (i.e. Harry Potter Invisibility Cloak), as well as for optical polarizers for sunglasses.
"We are very excited at the potential applications of these nanorods, said Christian Schoen, President of Nanopartz.
For more information, visit Nanopartz at
Source: Nanopartz (press release)
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