The appliance of nanoscience
How are nanoparticles used?
The medical potential of nanotechnologies is huge. Already on the market in the USA are wound dressings that exploit the antimicrobial properties of nanocrystalline silver.
Gold nanoparticles, often coated in special polymer materials, are being tested in numerous clinical trials. They can be applied in a number of ways, such as to deliver drugs inside cells or to kill cancer cells from within.
Nanomaterials make good implants. Nanocrystalline zirconium oxide (zirconia) and silicon carbide are strong, lightweight, resistant to wear and corrosion and, unlike many other nanoparticles, inert. In California scientists have used yttria-stabilised zirconia to make transparent implants. These could be set into the skull, allowing access for cutting-edge techniques using lasers to treat the brain in cases of stroke, cancer or neurological disorders.
There are environmental concerns about nanoparticles, but they could also play an important role in protecting the environment.
Self-cleaning windows have been developed with a special nanotechnology coating. When the sun shines on the glass, it starts a chemical reaction in the coating that breaks down any dirt on the surface. Rain then washes the dirt away.
The same coating has been adapted to remove nitrogen oxide pollution from the air.
Titanium dioxide and zinc oxide are already used in sunscreens. Because of their nano size, these particles absorb and reﬂect UV light while being transparent to visible light.
The cosmetics industry has invested heavily in nanotechnology. New products are claimed to penetrate deeper into the skin or to have other beneﬁts. For example, cosmetics that slowly release vitamins are in development.
Researchers are working on fabrics that use nanotechnology too: in the future we might be wearing clothes that store energy from our movements, or which have a built-in, flexible video screen.