Nanotechnology refers to the purposeful manipulation of material at the atomic or molecular scale, and the creation of useful materials by working at this scale. Depending on how our abilities with nanotechnology develop, one can hardly name a field or industry that will not be impacted. Many industries can expect important developments, even transformation: semiconductors, computing, publishing, food, clothing, advertising, construction, materials, environmental mitigation, lighting, energy, security, vehicles, the military, manufacturing, and the list goes on.
One domain that may be significantly impacted is medicine. Imagine injecting a swarm of nanotech devices into the body, having those devices seek out cancer cells, and then selectively destroying the diseased cells with little or no damage to surrounding tissue. This is surely and only the stuff of science fiction movies, right? Get ready, human trials begin in December 2003.
Specifically, two variations on using gold nanoparticles are in the works. In one method, a gold-coated nanoshell (think of a soccer ball), 10,000 times smaller than a white blood cell, is manufactured. It consists of layered gold atoms wrapped around a globe of silica. Millions are suspended in a liquid and injected. Cancer-specific antibody proteins imbedded in the gold shell seek out tumor cells and attach themselves. Once the nanoshells have attached to tumor sites, something made visible by illuminating the body with near-infrared light, the specific tumor sites are illuminated with a more intense ray of light. The nanoshells heat up while surrounding tissue does not, and the nanoshells ‘cook’ the tumor. All of this in a single visit to the doctor, by the way.
Funded by the Department of Defense, and researched at Rice University by Naomi Halas and Jennifer West, this treatment is to be tried first on breast cancer with preliminary trials scheduled for 2004.
Another technique also using gold nanoparticles is set for human trials in December 2003, animal models having been successful. CytImmune Sciences of College Park, Maryland is partnering with OctoPlus of the Netherlands to deliver an anticancer protein, tumor necrosis factor (TNF) using colloid gold nanoparticles. TNF has been shown to have significant cancer killed potential, but has never been delivered without serious side effects. When hitched to colloid gold nanoparticles however, TNF has been delivered in safe doses in animal models. In the research stage for eight years, researchers have found that TNF binds to the surface of colloid gold. Reducing the saturation of TNF on each nanoparticle by placing linear pieces of polyethylene glycol between TNF molecules, the researches have managed to deliver the proper dose.
The gold nanoparticles are typically 25 nanometers in size, small enough to pass through holes in blood vessels that surround tumors, but too large to enter any organs through normal blood vessels. Using this strategy, the researchers have found they can deliver 10 times more TNF to tumors than before, with precise targeting. If the clinical trials are successful, a product should be available to the market in 2007.
