U.S. scientists have succeeded in making unique nanoscale droplets that are much smaller than a human cell and can potentially be used to deliver pharmaceuticals.

"What we found that was unexpected was within each oil droplet there was also a water droplet -- a double emulsion," Timothy Deming, lead researcher from University of California, said Thursday in a statement. "We have a water droplet inside of an oil droplet, in water."

Emulsions are droplets of one liquid in another liquid; the two liquids do not mix. The big challenge was to make these double-emulsion droplets in the sub-100-nanometer size range with these properties and have them be stable.

"This gives us a new tool, a new material, for drug delivery and anticancer applications," said another researcher Thomas Mason. They have made nanoemulsions containing billions of double nanodroplets. Their research, reporting on droplets smaller than 100 nanometers -- the world' + char(39)+ N's smallest double emulsions – appears in the Sept. 4 edition of the journal Nature and is currently online.

The researchers caution that while this approach holds promise for fighting cancer, there are still many steps, and likely many years of research, before patients could be treated in this way. Clinical trials using this research would probably be years off.

In future research, they want to make sure the droplets can harmlessly enter cells and release their cargo.

The nanodroplets could potentially be used in cosmetics, soaps and shampoos as well, said the research team.