During the Middle Ages, philosophers attempted to transmute base materials into gold in a process called
alchemy. While their efforts proved fruitless, the pseudoscience alchemy paved the way to the real science of chemistry. Through chemistry, we learned more about the world around us, including the fact that all matter is composed of
atoms. The types of atoms and the way those atoms join together determines a substance's properties.
Nanotechnology is a multidisciplinary science that looks at how we can manipulate matter at the molecular and atomic level. To do this, we must work on the
nanoscale -- a scale so small that we can't see it with a light microscope. In fact, one nanometer is just one-billionth of a meter in size. Atoms are smaller still. It's difficult to quantify an atom's size -- they don't tend to hold a particular shape. But in general, a typical atom is about one-tenth of a nanometer in diameter.
But the nanoscale is where it's at. That's because it's the scale of molecules. By manipulating molecules, we can make all sorts of interesting materials. But like the alchemists of old, we wouldn't make much headway in creating gold. That's because gold is a basic
element -- you can't break it down into a simpler form.
We could make other interesting substances, though. By manipulating molecules to form in particular shapes, we can build materials with amazing properties. One example is a carbon nanotube. To create a carbon nanotube, you start with a sheet of graphite molecules, which you roll up into a tube. The orientation of the molecules determines the nanotube's properties. For example, you could end up with a conductor or a
semiconductor. Rolled the right way, the carbon nanotube will be hundreds of times stronger than steel but only one-sixth the weight [source:
NASA].
That's just one aspect of nanotechnology. Another is that materials aren't the same at the nanoscale as they are at larger scales. Researchers with the United States Department of Energy discovered in 2005 that gold shines differently at the nanoscale than it does in bulk. They also noticed that materials possess different properties of magnetism and temperature at the nanoscale [source:
U.S. Department of Energy].
Because the science deals with the basic building blocks of matter, there are countless applications. Some seem almost mundane -- nanoparticles of zinc oxide in sunblock allow you to spread a transparent lotion on your skin and remain protected. Others sound like science fiction -- doctors are attempting to use the protein casings from viruses to deliver minute amounts of drugs to treat cancer. As we learn more about how molecules work and how to manipulate them, we'll change the world. The biggest revelations will come from the smallest of sources.
There's an unprecedented multidisciplinary convergence of scientists dedicated to the study of a world so small, we can't see it -- even with a
light microscope. That world is the field of nanotechnology, the realm of
atoms and nanostructures. Nanotechnology is so new, no one is really sure what will come of it. Even so, predictions range from the ability to reproduce things like diamonds and food to the world being devoured by self-replicating nanorobots.
In order to understand the unusual world of nanotechnology, we need to get an idea of the units of measure involved. A centimeter is one-hundredth of a meter, a millimeter is one-thousandth of a meter, and a micrometer is one-millionth of a meter, but all of these are still huge compared to the nanoscale. A
nanometer (nm) is one-billionth of a meter, smaller than the wavelength of visible light and a hundred-thousandth the width of a human hair [source:
Berkeley Lab].
As small as a nanometer is, it's still large compared to the atomic scale. An atom has a diameter of about 0.1 nm. An atom's nucleus is much smaller -- about 0.00001 nm. Atoms are the building blocks for all matter in our universe. You and everything around you are made of atoms. Nature has perfected the science of manufacturing matter molecularly. For instance, our bodies are assembled in a specific manner from millions of living
cells. Cells are nature's nanomachines. At the atomic scale, elements are at their most basic level. On the nanoscale, we can potentially put these atoms together to make almost anything.
In a lecture called "Small Wonders:The World of Nanoscience," Nobel Prize winner Dr. Horst Störmer said that the nanoscale is more interesting than the atomic scale because the nanoscale is the first point where we can assemble something -- it's not until we start putting atoms together that we can make anything useful.
In this article, we'll learn about what nanotechnology means today and what the future of nanotechnology may hold. We'll also look at the potential risks that come with working at the nanoscale.
Photographer: Jean-louis Bouzou Agency: Dreamstime.com
Nanoparticles derived from gold hold tremendous possibilities for scientific and medical use. See more modern medicine pictures.
In a study published in the July 2007 issue of Analytical Chemistry, scientists from Purdue University detailed their use of
gold nanoparticles to detect
breast cancer. Their work, along with similar studies at other universities, has the potential to radically change breast cancer detection.
The procedure works by identifying the proteins found on the exteriors of
cancer cells. Different types of cancer have different proteins on their surfaces that serve as unique
markers.
Nanorods, gold nanoparticles shaped like rods, use specialized antibodies to latch onto the protein markers for breast cancer, or for another cancer type. After the nanorods bind to proteins in a
blood sample, scientists examine how they scatter
light. Each protein-nanorod combination scatters light in a unique way, allowing for precise diagnoses.
The use of gold nanoparticles is not new to this study. These tiny particles -- it would take 500 of them to span the width of a human hair -- are particularly suited to detect toxins, pathogens and cancers and are a subject of much experimentation [Source:
BBC News]. The scientists at Purdue used nanorods capable of attaching to three types of breast cancer markers, with two of the markers identifying how invasive the cancer is. The lead researcher on the study, Joseph Irudayaraji, said that these nanorods could one day form part of a much more thorough test, binding to up to 15 unique markers [Source:
Physorg].
Using nanorods cuts the price of the diagnosis by two-thirds compared to the similar method of
flow cytometry, in which fluorescent markers bind to cancer cells. Flow cytometry requires a bigger sample size with thousands of times more cells than is needed for nanorods, meaning that nanorods are capable of helping to determine earlier diagnoses. Nanorods prove much less invasive than some other methods because they use blood samples and don't require a
biopsy. Part of the cost savings comes from scientists being able to use a conventional
microscope and light source to view the samples, unlike other methods that employ expensive microscopes or
lasers.
In a different study, Dr. Irudayaraj showed that gold nanorods could be used to detect
cancer stem cells. The discovery is particularly valuable because cancer stem cells cause the out-of-control growth that makes malignant tumors so deadly.
Dr. Irudayaraji said that gold nanoparticles could be widely available for cancer diagnoses sometime in 2011.
Besides being part of exhaustive tests that can detect cancers early on, nanoparticles may also form the basis of future cancer treatments. Lasers that react with gold nanoparticles could be used to destroy cancer cells. Or, nanoparticles could be used as targeted drug-delivery systems.
Nanotechnology and Cancer
Photographer: Juan Lobo | Agency: Dreamstime.com
Nanotechnology cancer treatments would use gold particles to carry anticancer drugs straight to the cancer. Learn about nanotechnology cancer treatments.
Nanotechnology is one of the most popular areas of scientific research, especially with regard to medical applications. We've already discussed some of the new detection methods that should bring about cheaper, faster and less invasive
cancer diagnoses. But once the diagnosis occurs, there's still the prospect of surgery, chemotherapy or radiation treatment to destroy the cancer. Unfortunately, these treatments can carry serious side effects. Chemotherapy can cause a variety of ailments, including hair loss, digestive problems, nausea, lack of energy and mouth ulcers.
But nanotechnologists think they have an answer for treatment as well, and it comes in the form of
targeted drug therapies. If scientists can load their cancer-detecting gold nanoparticles with anticancer drugs, they could attack the cancer exactly where it lives. Such a treatment means fewer side effects and less medication used. Nanoparticles also carry the potential for targeted
and time-release drugs. A potent dose of drugs could be delivered to a specific area but engineered to release over a planned period to ensure maximum effectiveness and the patient's safety.
These treatments aim to take advantage of the power of nanotechnology and the voracious tendencies of cancer cells, which feast on everything in sight, including drug-laden nanoparticles. One experiment of this type used modified bacteria cells that were 20 percent the size of normal cells. These cells were equipped with antibodies that latched onto cancer cells before releasing the anticancer drugs they contained.
Another used nanoparticles as a companion to other treatments. These particles were sucked up by cancer cells and the cells were then heated with a magnetic field to weaken them. The weakened cancer cells were then much more susceptible to chemotherapy.
It may sound odd, but the dye in your blue jeans or your
ballpoint pen has also been paired with gold nanoparticles to fight cancer. This dye, known as
phthalocyanine, reacts with
light. The nanoparticles take the dye directly to cancer cells while normal cells reject the dye. Once the particles are inside, scientists "activate" them with light to destroy the cancer. Similar therapies have existed to treat skin cancers with light-activated dye, but scientists are now working to use nanoparticles and dye to treat tumors deep in the body.
From manufacturing to medicine to many types of scientific research, nanoparticles are now rather common, but some scientists have voiced concerns about their negative health effects. Nanoparticles' small size allows them to infiltrate almost anywhere. That's great for cancer treatment but potentially harmful to healthy cells and
DNA. There are also questions about how to dispose of nanoparticles used in manufacturing or other processes. Special disposal techniques are needed to prevent harmful particles from ending up in the water supply or in the general environment, where they'd be impossible to track.
Gold nanoparticles are a popular choice for medical research, diagnostic testing and cancer treatment, but there are numerous types of nanoparticles in use and in development. Bill Hammack, a professor of chemical engineering at the University of Illinois, warned that nanoparticles are "technologically sweet" [Source:
Marketplace]. In other words, scientists are so wrapped up in what they can do, they're not asking if they should do it. The Food and Drug Administration has a task force on nanotechnology, but as of yet, the government has exerted little oversight or regulation.
For more information on nanoparticles, medical research and other related topics, please check out the links on the next page.
Safira de Wit, Miss Curacao 2010; and Giuliana Zevallos, Miss Peru 2010, pose in their swimsuits. Curacao is an in the southern Caribbean Sea, with a population of just under one and half lakhs!
