Super-sensitive rapid cancer biomarker test uses gold nanoparticles, dynamic light scattering

MAY 5, 2009--Feasibility studies of a new test for rapid cancer detection show that the test is highly sensitive, easy to use, and could enable major improvements in early cancer diagnosis. Called nanoDLSAY, it uses dynamic light scattering and gold nanoparticle probes to detect cancer biomarkers. The test shows promise for detecting other diseases and conditions as well as for research, and is expected to be commercially available beginning in three years.

MAY 5, 2009--Feasibility studies of a new test for rapid cancer detection developed at the University of Central Florida (Orlando, FL) have shown that the test is highly sensitive, very easy to use, and has the potential to provide major improvements in early cancer diagnosis. The test is based on nanotechnology called nanoDLSAY, and it claims to be the first test to use dynamic light scattering and gold nanoparticle probes to detect cancer biomarkers. Gold nanoparticles are very stable and have strong light scattering properties, much more so than biomolecules and polymer particles, and therefore can be detected by dynamic light scattering with high sensitivity at very low levels. Such highly sensitive tests will be very valuable for early cancer detectionand also for monitoring cancer recurrence after surgery.

The in vitro procedure involves exposing a sample of the patient's blood or serum to gold nanospheres covered with antibodies against a particular cancer biomarker. These nanospheres attach to and surround biomarkers in the sample. A beam of light is then shone through the sample and measurements of the scattered light can quantify the size of nanospheres in the solution, and therefore the concentration of the cancer biomarker.

The nanoDLSAY technology was developed by Professor Qun Huo, associate professor at the University of Central Florida's NanoScience Technology Center. To bring this technology to market, Professor Huo started a company called Nano Discovery, LLC. Professor Huo's research at Nano Discovery LLC is supported by the World Gold Council's (WGC) Gold Research Opportunities Worldwide (GROW) Program, which co-funds potential new scientific and industrial uses of gold.

The test is simple and involves a single-step procedure that requires only a very small sample. It is also cost effective and can be carried out quickly--typically within a few minutes to a half hour--in either central clinical testing labs or point-of-care facilities such as hospitals, clinics, and doctors' offices.

Besides in vitro diagnostics, the platform technology can also be used for research and for drug screening and development by the pharmaceutical industry. And though the technique was developed initially for screening prostate and other cancers, it can also be applied to other human diseases and conditions such as infectious and sexually transmitted diseases, neurodegenerative diseases, and cardiovascular diseases; and for illegal performance drug monitoring and biodefense.

Professor Huo's company will seek to partner with a dynamic light scattering (DLS) manufacturing company to co-develop a prototype DLS instrument that is specifically designed to conduct the nanoDLSAY. Prototype products will then undergo product testing in selected locations in the U.S. medical community; the test should be available for research purposes within three years and to the diagnostic market in three to five years.

According to Dr. Richard Holliday at the World Gold Council, "The properties of gold have long been applied to medicine and science. This development shows that the metal, which has been around for thousands of years, is still being used in the most advanced scientific processes to find new ways to diagnose and fight modern illnesses. The GROW program has been successful in identifying and supporting this very valid and relevant research. This is our first significant project in this area, but the biomedical applications for gold are an important area that we will continue promoting in the future."

Use of gold in the treatment of cancer dates back to 1955. More recently, new treatment technologies under development rely on the ability of tiny gold nanoparticles to specifically collect in a cancerous tumor by passing through leaky blood vessels attached to a tumor. So, when injected into a patient, there is a means by which a potent anti-cancer compound attached to a gold nanoparticle, can be directly and accurately delivered to a tumor while avoiding healthy body tissue. Such an effective drug delivery mechanism with reduced toxicity is considered to be a major step-forward, limiting such side effects as lowered immunology and hair loss.

World Gold Council (WGC) is a commercially-driven marketing organization funded by the world's leading gold mining companies. The WGC's Gold Research Opportunities Worldwide (GROW) Program co-funds potential new scientific and industrial uses of gold. It is supported by a long-established and extensive network of experts, the Editorial Board of World Gold Council's peer reviewed journal Gold Bulletin, and the Technical Committees of World Gold Council scientific conferences, who provide technical advice to the programme.

For more information on the nano gold/DLS technology for cancer detection, please see the 2008 paper A One-Step Homogeneous Immunoassay for Cancer Biomarker Detection Using Gold Nanoparticle Probes Coupled with Dynamic Light Scattering in the Journal of the American Chemical Society. See also information on the World Gold Council's funding programs and the WGC itself.

Posted by Barbara G. Goode,, for BioOptics World.

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