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Fundamentally, nanotechnology is about making things on the scale of atoms. By manipulating matter on the atomic and molecular scale, it is possible to create new materials and devices that can be smaller, stronger or faster; for example carbon nanotubes possess extraordinary strength and unique electrical properties, and have been described as 'the most important material in nanotechnology today'.¹

Nature also works on the molecular scale. Naturally occurring molecular assemblies that regulate and control biological systems are the most complex and highly functional nanoscale processes we know. The volume of a single molecule biodevice, such as a protein, is between one-millionth and one-billionth of the volume of an individual cell. If these natural processes were fully understood it might be possible to influence or interact with them, opening a new path to innovative pharmaceuticals. It could also be possible to stimulate the body to successfully repair diseased or damaged tissues.

However, predicting the impact of new technologies is difficult and there are many concerns regarding the use of nanotechnology, including what unintended and unwanted effects it could have on the environment and human health.

An invisible world

On the go...

Nanotechnology can be defined in a number of ways, but is usually accepted as 'the ability to do things — measure, see, predict and make — on the scale of atoms and molecules, and exploit the novel properties found at that scale'.² The units of measurement involved are difficult to comprehend. A single nanometer is equivalent to one thousandth of a micron or one billionth of a metre, which has been likened to comparing the size of a marble to the size of the Earth.³

Although open to interpretation, the nanoscale is generally said to comprise anything measuring 1–100 nm. At this scale, materials often exhibit different physical, chemical and biological properties; for example, the melting point of a substance may change because of the change in surface area, chemical activity may increase or a substance may acquire the ability to cross tissue barriers. This creates new possibilities to optimize drug targeting and delivery. In what is reminiscent of a science fiction novel, researchers have also speculated that it could be possible to use nanorobots that patrol the body diagnosing and treating ailments.⁴

Many of these medical and pharmaceutical applications may not be possible for many years, as any product would have to be subjected to strict testing and validation procedures. However, there are already hundreds of products on the market that utilize nanotechnology, many of which we use in our daily lives including batteries, computers, kitchenware, clothing, cosmetics, toothpastes, sun creams and paints. It has been estimated that nanotechnology consumer products are coming on the market at a rate of 3–4 per week.⁵ Nanotechnology is also used in some pharmaceuticals, such as Abraxine, which was recently launched in India by Biocon (India) and Abraxis BioScience (CA, USA),⁶ and is available in more than 30 countries. The drug is administered as albumin-bound particles of approximately 130 nm.

Origins

The first documented introduction to nanotechnology is Richard Feynman's lecture entitled "There's Plenty of Room at the Bottom", which he gave at an American Physical Society meeting in 1959. Although the term nanotechnology was not used then, Feynman spoke about the possibility of manipulating matter on the atomic scale. However, nanotechnology and nanoparticles had unintentionally been used long before this by glaziers in medieval forges who produced colours with gold nanoparticles of different sizes to decorate glass.

It wasn't until 1974 that the term 'nanotechnology' was used by Norio Taniguchi from the Tokyo Science University (Japan) to describe precision micromachining, and discussions regarding the topic didn't really take place until 1980s. That decade saw the invention of the scanning tunnelling microscope, publication of the first nanotechnology book, Kim Eric Drexler's Engines of Creation: The Coming Era of Nanotechnology, and the formation of the Foresight Nanotech Institute (CA, USA) — the first organization dedicated to educate society about the benefits and risks of nanotechnology. At the end of the decade, it was also discovered that the scanning tunnelling microscope could be used to move single atoms when IBM scientist, Don Eigler, moved individual atoms of xenon gas to spell out the IBM logo. The ability to accurately position individual atoms led to other new discoveries; for example, Eigler's team later created a wall of iron atoms to study how electrons behaved in tightly constrained spaces.