Nanoparticles: Good News, Bad News
Everywhere you look these days you see references to nanotechnology. For the curious generalist there is even a Nanotechnology for Dummies volume in the familiar yellow-covered series.
The scientific literature, too, is replete with nanotech work from all manner of researchers and all corners of the globe. Two caught my eye recently, exemplifying both the promise and the peril, at least in biomedical application.
On the positive side of the ledger, a bicoastal research team from California and Massachusetts published new results on the use of “nanoworms” in anticancer diagnostics and therapy (Advanced Materials 20 (2008): 1630-1635). Such beasties are composed of both iron oxides and dextran, the former useful in MRI imaging and the latter helpful in escaping the normally rapid and efficient body elimination processes. By controlling the size and shape of the nanoworms, the researchers were able to demonstrate very effective tumor targeting in mice.
A darker cloud was raised by an English/American collaboration demonstrating asbestos-like toxicity when carbon nanotubes are injected into the abdominal cavity of mice. (Nature Nanotechnology, published online May 20, 2008). Such nanotubes are widely available, so toxicity studies were eminently predictable. So far, though, the results do not address the biggest bugaboo about asbestos, namely induction of the nasty type of lung cancer called mesothelioma.
Since the aspect ratio of the fibers (and the nanoworms) is more important than the chemical composition in determining biological response, one anticipates that clever materials scientists will be able to engineer out dangerous toxicities. Still, the juxtaposition of these two studies illustrates the inevitable yin and yang of all emerging technologies.