Nanotechnology: The size of things to come
(1 January 2006: VIDYYA MEDICAL NEWS SERVICE) -- By Carol Rados
In today's world of biomedical tools and therapies, researchers are thinking big by thinking small with the arrival of pocket-sized electrocardiographs for monitoring the heart and diagnostic cameras the size of a vitamin pill that travel the length of the digestive tract.
These days, scientists are downsizing to the "nano" scale. Nanotechnology deals with the creation and use of materials or devices at the level of molecules and atoms that are 1/1000th the width of a human hair--too small to be seen with a conventional laboratory microscope.
Nanomedicine is an area of biomedical research that seeks to use tools from the field of nanotechnology to improve health. Scientists say that the physical, chemical, and biological properties of materials at the nanoscale differ in fundamental and valuable ways from the properties of larger-sized matter.
Nanotechnology is changing the way materials and devices will be made in the future. With the ability to build products and devices atom-by-atom and molecule-by-molecule, according to the National Nanotechnology Initiative (NNI)--a federal research and development program--scientists will create new classes of structural materials that are expected to bring about lighter, stronger, smarter, cheaper, cleaner, and more precise products.
For example, nanotechnology could provide new formulations and new routes to deliver drugs to previously inaccessible sites in the body, thereby broadening a drug's potential. Tiny sensors that detect diseases in the body far earlier than existing diagnostic tools, and pumps the size of molecules implanted to deliver lifesaving medications precisely where they are needed, are among the promising areas of research.
According to the NNI, more powerful nanotechnology developments expected in the next 10 years likely will include solutions to repair and rearrange living cells.
The Smaller, the Better?
Nanotechnology allows scientists to work on the scale of molecules to create, explore, and manipulate the biological and material worlds measured in nanometers, one-billionth of a meter. By way of comparison, a sheet of paper is about 100,000 nanometers thick; a human hair is about 80,000 nanometers wide. A nanometer-sized particle is smaller than a cell in your body, which means that nanodevices someday may be small enough to interact with human genes and proteins. This interaction would enable scientists to study the functions of healthy as well as diseased cells more carefully.
Much of today's nanoscale research is designed to reach a better understanding of how matter behaves on this small scale. According to the National Cancer Institute, the factors that govern larger systems do not necessarily apply at the nanoscale.
For example, detection and diagnosis of cancer today relies on changes in cells and tissues that are detected by a physician's physical touch or by imaging expertise. But scientists would like to detect molecular changes earlier, long before a tumor could be detected during a doctor's exam or by imaging technology. To do this, they would need special tools capable of probing the micro-world of nanometers. And body-friendly nanotools will help scientists figure out how to build synthetic biological medical devices and programmable systems in miniature.
Some of the challenges anticipated by nanotechnology include the uncertain reaction of nanostructures within the body, and those devices or systems that may be so small that the body clears them too soon to be effective in detecting or imaging. Another possibility is that nanoparticles may accumulate in vital organs, creating a toxicity problem.
Regulating a Rapidly Growing Industry
As more complex products based on emerging nanotechnologies surface, the Food and Drug Administration faces an increasing challenge to regulate a rapidly growing industry. Many approved products now on the market are manufactured with or contain components in the nanoscale range. To date, the agency has not received any adverse reaction reports related to the small size of drug or medical device products.
For the most part, FDA experts believe that existing regulatory standards are probably adequate for most nanotechnology products. Scientists say that particle size is not the issue. Instead, new tests and standards will be required as new toxicological risks from the new materials are identified.
The FDA expects that many of the nanotechnology products it will regulate will span the regulatory boundaries between drugs, medical devices, and biologics, for example, a drug delivery device. These, then, would be regulated under the rules established by law for "combination products."
In addition, the FDA has limited authority over regulating certain categories of products. Therefore, the agency could just as likely have limited authority over the use of nanotechnology related to those products. For example, there is no pre-market approval of cosmetic products or their ingredients, except color additives.
Special consideration of nanotechnology products is important because this is a rapidly growing area of science that the FDA anticipates will lead to the development of novel and sophisticated, and perhaps complex, products.
Current uses of nanotechnology include:
- burn and wound dressings
- a dental-bonding agent
- protective and glare-reducing coatings for eyeglasses.
- water filtration
- step assists on vans
- longer-lasting tennis balls
- stain-free clothing and mattresses
- display technology for laptop computers, cell phones, and digital cameras.
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