Rust and sand could help detect cervical cancer, diarrhea
By ANITuesday, February 1, 2011
WASHINGTON - Scientists in Vietnam say that the next big thing in medical diagnostics could be magnetic nanoparticles of rust (iron oxide) coated with silicon dioxide, the material from which sand is formed.
These nanoparticles, ranging from 29 to 230 nanometers across, could be used to trap antibodies to the virus causing cervical cancer or to the bacteria that cause potentially deadly diarrhoea.
Scientists said it was not so difficult to immobilize on nanoparticles, synthetic or monoclonal antibodies that respond to the human papilloma virus, HPV18, and the toxic gut microbe Escherichia coli O157:H7.
Once the antibodies are trapped, they can be exposed to a potentially contaminated sample. If pathogen particles are present, some will stick to the antibodies and this change can then be detected by a conventional test or analysis.
Conventional techniques have been accurate so far, but having the magnetic nanoparticles improves the limits of detection by allowing just these particles to be separated from the sample before the test, so that there are no residual cells or other substances that can interfere with the assay.
For example, E. coli could be detected in a sample at much lower number of bacterial cells than normal, allowing a much more precise and faster tracking of the contamination source.
Also, an improved detection limit for the presence of HPV18 in cells of the cervix could help reveal problems sooner than standard screening tests, thus improving the chances of successful treatment for cervical cancer.
According to Tran Hoang Hai of the Ho Chi Minh City Institute of Physics and colleagues, cervical cancer is the second most common form of cancer after breast cancer in women worldwide.
The conventional enzyme-linked immunosorbent assay (ELISA) diagnosis, however, does not reveal the presence of cancerous cells at the very earliest stage.
Similarly, E. coli O157:H7 is an extremely common cause of severe diarrhoea, which can, in some cases, lead to kidney failure and sometimes death.
The magnetic nanoparticle approach could be a solution to both these situations, added the scientists. (ANI)
