Cancer tests are so expensive that they are administered only when there is compelling evidence of disease potential. But a new technology1 offers cost effective and fast detection within a few minutes to a half hour–and the inventor hopes it will one day be available to consumers in supermarkets and pharmacies.
The test has proven highly sensitive and easy to use in feasibility studies. Called Nano-DLSay, it claims to be the first test to use dynamic light scattering (DLS; see bioopticsworld.com/articles/336941) and gold nanoparticles (see bioopticsworld.com/ articles/350044). Professor Qun Huo, associate professor at the University of Central Florida’s (Orlando, FL) NanoScience Technology Center, developed the technology and launched a company (Nano Discovery, LLC) to commercialize it.
Huo told BioOptics World that her innovation is based on the fact that metal scatters light more strongly than, say, polymer or biomolecules. In particular, gold nanoparticles have a large scattering cross section around the surface plasmon resonance wavelength region.
The simple, in-vitro test involves a single-step procedure and requires only a very small sample of blood. Huo explains that the sample is exposed to two types of gold nanospheres in solution, each engineered to bind to an antibody associated with a particular cancer biomarker. An antigen from the solution “glues” the particles together so that the nanoparticles, in effect, increase in size. When light is shone through the sample, measurements of the scattered light can quantify the size of nanospheres–and therefore the concentration of the cancer biomarker.
Such highly sensitive tests will be very valuable for early cancer detection and also for monitoring cancer recurrence after surgery. 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. “It’s a platform technology,” says Huo, noting that it could work for any protein target–and indeed a paper published last year describes its use for DNA detection.2 Thus, it could also be used for research and for drug discovery and development.
Huo is working with Dr. Cheryl Baker of M.D. Anderson Cancer Center Orlando to test the technology with human and animal serums, and is in discussion with DLS manufacturing companies. Her goal is to partner with such a company to co-develop a prototype DLS instrument specifically designed to conduct the NanoDLSay. The test should be available for research purposes within three years, and to the diagnostic market in three to five years. –Barbara G. Goode
- X. Liu et. al. J. Am. Chem. Soc. (2008) 130, 2780-2782.
- Q. Dai et. al. J. Am. Chem. Soc. (2008) 130, 8138-8139.