Scientists at UCSD in California
have developed nanometer-sized ‘nanoworms’ that can travel through the
bloodstream without significant interference from the body’s immune
defense system to become tiny anti-cancer missiles and home in on
tumours. Isn’t that amazing?
The nanoworms essentially form spherical iron oxide nanoparticles that join together,
like segments of an earthworm, to produce microscopic worm-like
structures about 30 nanometers long, or about 3 million times smaller
than an earthworm. The iron-oxide allows the nanoworms to
show up brightly in diagnostic devices such as magnetic resonance imaging (MRI), which are used to scan pictures of tumours.
Nanoparticles are usually recognised by the body’s protective immune
system as foreign, so they are captured, disabled and removed from the
bloodstream within minutes. The reason this idea works effectively is
due to a combination of their shape and a polymer coating on their
surface, allowing the nanoworms to evade these natural elimination
processes. They have been shown to circulate in the body of a mouse for
So what’s the point of this cool technology idea?
Well, if the nanoparticles were mixed with chemotherapy, they could
offer doctors the ability to increase the efficacy of cancer drugs by allowing
them to deliver the chemo more directly to the tumours, as a sort of
trojan horse or stealth technology strategy. This would potentially
decrease the side effects of toxic anti-cancer drugs by limiting their
exposure to normal tissues and targeting the tumour cells, where you
want them to do their damage. A similar approach might work for HIV
infections too, for example.
You’ve heard of silver bullets, but these nanobullets might be a
commonplace sci-fi tool in the not so distant future. If they make
chemotherapy or HIV therapies more effective and less toxic, that’s no
bad thing for patients.
Source: Cancer Research Center, La Jolla, CA [Free article download]