When I first saw the link to this story, I thought it was yet another illuminated nanospheres zapping cancer report; after all, lots of places appear to be working on that technology, so we should start seeing more results in the months to come. This one turns out to be different, however: University of Delaware researchers have put together a system that quite literally blows apart cancerous tissue with minimal damage to nearby healthy cells. The research was reported in the journals NanoBiotechnology and Oncology Issues.
Dr. Balaji Panchapakesan, assistant professor of electrical and computer engineering, and his team at the University of Delaware were looking at the optical and thermal properties of carbon nanotubes, trying to find ways to improve their use as drug delivery mechanisms.
As they undertook various experiments, however, the team made a startling discovery. “When you put the atoms in different shapes and forms, they take on different properties at the nanoscale,” Panchapakesan said. “We were experimenting with the molecules and considering optical and thermal properties, and found we could trigger microscopic explosions of nanotubes in wide variety of conditions.”
Explosions in air of loosely packed nanotubes have been seen before in an oxygen environment, creating ignition. However, the work reported by Panchapakesan uses the localized thermal energy imbalance to set off explosions that are intrinsic in nature.
Panchapakesan said the nanobombs are just that, tiny bombs on the nanoscale. “They work almost like cluster bombs,” he said. “Once they are exposed to light and the resulting heat, they start exploding one after another.”
The bombs are created by bundling the carbon nanotubes. With a single nanotube, the heat generated by the light is dissipated by surrounding air. In bundles, the heat cannot dissipate as quickly and the result is “an explosion on the nanoscale,” Panchapakesan said.
One important aspect of the "nanobombs" is that the carbon nanotubes are destroyed along with the cancer cells, and the body can readily clean up the remaining material. This would ensure that the nanotubes themselves don't become sources of toxic reactions. Dr. Panchapakesan is focusing the initial work on attacking breast cancer, but plans to expand the research to cover pancreatic and prostate cancer, as well.
It's very interesting to see how the reality of nanomedicine matches up against early scenarios. Some of the more compelling ideas about molecular nanotechnology in the early days involved nanobots roving through the bloodstream, clearing out cholesterol, tearing apart cancer, and generally acting like a super-smart immune system. While such a technology may still come about at some point, it's good to see that useful, innovative medical techniques are emerging from the nanomaterial era of nanotechnology, and don't have to wait until we've figured out how to pack a robotic mind into something the size of a cell.
Moreover, it's important to note that this came from a kind of interdisciplinary research that would have been inconceivable not too many years ago. Panchapakesan studies electrical and computer engineering; even now, few people would imagine that medical breakthroughs would come from someone working in the computer engineering building. It's one of the possibly unexpected benefits of the increasing connections between bioscience and other sciences -- we don't just get biomimicry, we get non-biologists suddenly seeing how the work they've been doing has biological applications.
How does the light reach the nanotubes?
Unspecified in the report. They're currently not doing in-vivo testing, but I would expect that the process would use an infrared laser at a frequency that can pass through living tissue. That's how the other light-activated nanomaterial anti-cancer treatments work.
How are these "nanobombs" put into position before detonation?
Right now, this is entirely an in-vitro (i.e., in a petri dish) process, not yet something that has been tested on cancer cells in a living animal.
There are various ways the material could be delivered, however, from direct injection to encapsulation in gold nanospheres (gold and silver nanospheres tend to get 'stuck' in cancer cells).
reminds me of the brutal criminal justice system in "The Diamond Age" by Neal Stephenson, in which everyone carries in their bloodstream implanted nanoexplosives that can be detonated by judges upon conviction for capital offenses...
and, of course, this research could be a great treatment for cancer...ho-hum...likely to be the story for most of nanotechnology.
Unless every single cell is destroyed by the explosion, won't this just promote metastasis?
When will the first real cancer cell destruction experiment take place? the project still seems to be pretty raw, though very interesting and promising