Gold Nanoparticles Shine Brightly in Tumors

Jan 16, 2008

Solid gold nanoparticles have long been used to treat rheumatoid arthritis and more recently have shown promise in treating various types of cancer. Now, thanks to work by Shuming Nie, Ph.D., and his colleagues at the Emory-Georgia Tech Nanotechnology Center for Personalized and Predictive Oncology, these same nanoparticles could serve as a powerful tumor-homing beacon for detecting microscopic tumors or even individual malignant cells. The researchers report their findings in the journal Nature Biotechnology.

Starting with colloidal gold—a commercially available suspension of gold nanoparticles—the investigators attached one of several positively charged organic dye molecules to the particles’ surfaces. The chosen dye molecules absorb and emit light in the near-infrared region of the spectrum, a portion of the spectrum that passes unabsorbed through biological tissues.

The researchers then added a nanometer-thick layer of polyethylene glycol (PEG) to render the construct biocompatible. To their surprise, this coating also made the resulting optical probe incredibly stable under even harsh chemical conditions. More importantly, the optical properties of both the gold nanoparticles and the dye molecules remained constant even after application of the coating. These particles were also nontoxic to cells over periods as long as 6 days.

These initial experiments showed that the coated gold nanoparticles could serve as potent imaging agents for studies of cancer cells, but the real goal of this project was to develop targeted in vivo imaging agents for detecting cancer in humans.

To prepare a targeted nanoparticle, the researchers used a version of PEG to which they could chemically link an antibody that binds to epidermal growth factor receptor (EGFR), a molecule overexpressed on many types of tumors. Antibodies and small molecules that bind to EGFR have been approved to treat non-small cell lung cancer.

The investigators injected the targeted nanoparticles into mice with EGFR-positive human head and neck carcinomas and obtained SERS spectra 5 hours later. As control experiments, the researchers injected matching mice with the untargeted nanoparticle. The unique optical spectra of the nanoparticles were easily detected in both sets of animals, but only the targeted nanoparticles accumulated in tumors. In contrast, the untargeted nanoparticles accumulated largely in the liver.

This work, which was supported by the National Cancer Institute’s (NCI) Alliance for Nanotechnology in Cancer, is detailed in the paper “In vivo tumor targeting and spectroscopic detection with surface-enhanced Raman nanoparticle tags.” An abstract of this paper is available through PubMed.

Source: National Cancer Institute

Explore further: Flower-like magnetic nanoparticles target difficult tumors

add to favorites email to friend print save as pdf

Related Stories

New nanodevice defeats drug resistance

Mar 02, 2015

Chemotherapy often shrinks tumors at first, but as cancer cells become resistant to drug treatment, tumors can grow back. A new nanodevice developed by MIT researchers can help overcome that by first blocking ...

Nanovectors combine cancer imaging and therapy

Feb 09, 2015

Researchers at Imperial College London and the Laboratoire de chimie de la matière condensée de Paris (CNRS/Collège de France/UPMC) have designed and developed hybrid gold-silica nanoparticles, which are ...

Recommended for you

Electrons moving along defined snake states

21 hours ago

Physicists at the University of Basel have shown for the first time that electrons in graphene can be moved along a predefined path. This movement occurs entirely without loss and could provide a basis for ...

New nanodevice defeats drug resistance

Mar 02, 2015

Chemotherapy often shrinks tumors at first, but as cancer cells become resistant to drug treatment, tumors can grow back. A new nanodevice developed by MIT researchers can help overcome that by first blocking ...

Glass coating improves battery performance

Mar 02, 2015

Lithium-sulfur batteries have been a hot topic in battery research because of their ability to produce up to 10 times more energy than conventional batteries, which means they hold great promise for applications ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.