A break from plastic electronics here, but not from chemistry, or even nanomaterials!

A group of scientists in Alberquerque, New Mexico, have synthesised superparamagnetic nanoparticles in a material with the functional ability to bind with cancerous cells. This allows the cancerous cells to then become themselves magnetized. A magnetic probe can then be used to collect the cancerous cells, removing the need for repeated invasion of the host to collect biopsies, which can be a painful as well as prove inaccurate.

A biologically compatible material is impregnated with these nanoparticles of magnetic iron oxide, and then coated with an antibody that binds indiscriminately with some cancer-based chemical. Hence, the material seeks and binds with the cancer, and the nanoparticulate superparamagnetic iron oxide magnetizes the system, enabling detection and capture with a magnetic probe.

The use of magnetic nanopartcles is common place now as part of several analytical procedures in medicine, the most common and famous being in MRI (magnetic resonance imaging). Here nanoparticles of iron oxide, such as the commercially available Feridex I.V. by Advanced Magnetics Inc., are used as contrast reagents and can be made to specifically target certain organs (Feridex I. V. targets liver lesions). Another use of magnetism in medicine is in the use of SQUIDs (superconducting quantum interference devices) to detect nanoparticles which have been attached by a similar method to above to T-cells, which allows an early and non-invasive method of detection of rejection of a transplant organ. The SQUID array is also used to allow an image of the targeted cells to be captured, and is so sensitive that only a few milligrams of the nanoparticles need to be injected.

I hope that this technology proves to be as useful (if not more!) than the paper suggests, as recently nanomaterials have got a bit of bad press due to their as-yet unknown long-term side-effects. I have personally done some work with nanomaterials (well, qunatum dots to be more precise) involving tagging with fluorescent dyes, and I must say how visually stunning the results are, as well as the ease of preparation. Unfortunately our exercise was purely academic (a ‘can we do it?’ mentality if you like) so there are no real results to report. However! This does not shake my belief that nanomaterials have still got a lot to offer, and although the side-effects are unknown, I hope the exciting research continues unabated.

For more on the aforementioned magnetization of cancer cells see Phys. Med. Biol. 2007 52 4009 and the article at NewScientist.co.uk

For more information on the use of SQUID arrays for determining transplant rejection see J. Magn. Magn. Mat. 2007 311 429.

For more information about nanomaterials and nanotechnology in general see the latest magazine edition of NewScientist.

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