14 DAY TRIAL // A team of scientists in Vietnam has discovered that the next big step in medical diagnostics could be magnetic nanoparticles of rust, iron oxide, coated with silicon dioxide, the material from which sand is formed.
These nanoparticles are ranged from 29nm to 230 nm across, and can be used to attach antibodies to the virus causing cervical cancer or to the bacteria that cause potentially deadly diarrhea.
The scientists say it's 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 and if pathogen particles are present, some will stick to the antibodies; this change will be detectable then 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, a better 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.
This diseases is the second most common form of cancer after breast cancer, in women worldwide, explain Tran Hoang Hai of the Ho Chi Minh City Institute of Physics and colleagues.
The problem with current techniques, is that the conventional enzyme-linked immunosorbent assay (ELISA) diagnosis does not reveal the presence of cancerous cells at the very earliest stage.
Also, E. coli O157:H7 is an extremely common cause of severe diarrhea, which can, in some cases, lead to kidney failure and sometimes death.
Because infection spreads very fast through ingestion of contaminated material, a rapid test that can spot contamination early is essential for stopping the spread of the disease.
The magnetic nanoparticle approach could remedy both these situations, added the authors.
This research was published in the International Journal of Nanotechnology.