1. Headline
  1. Headline
Image: Double bubble
Andrew Shinichi Utada  /  Harvard
A double-emulsion drop snaps off from a jet of two fluids within an outer fluid of viscous silicon oil. The middle fluid is water that contains a surfactant called sodium dodecyl sulfate, or SDS. The inner fluid is silicon oil. Researcher Darren Link says there's a poetry to the physics behind the technique. "I think it's art," he says.
By
Science
updated 4/21/2005 2:02:33 PM ET 2005-04-21T18:02:33

Scientists have discovered how to squeeze bubbles inside bubbles, which may offer a way to smuggle all sorts of substances — from expensive perfumes to cancer drugs — into places they couldn’t survive without protection.

The new method, developed by David Weitz of Harvard University and his colleagues, produces droplets in carefully controlled sizes, with multiple fluids nestling inside each other. The findings appear in Friday's issue of the journal Science, published by AAAS, the nonprofit science society.

Double bubbles at work
Some of the most ambitious hopes for these multilayered droplets are in medicine, where it would be essential to control the amount of drug being delivered.

Hiding a drug inside droplets could serve several purposes. Researchers might design the droplet to allow the drug to seep out gradually once it’s in the body. Or, if a treatment has two components that need to be kept separate, they could be put in different layers of the same droplet.

Someday — with a lot more research — it may even be possible to tag droplets with molecules that make them stick to a certain site, such as a tumor, where they can slowly release cancer drugs. Other types of droplets might be filled with insulin and targeted to certain sites in the bodies of diabetics.

Researchers in other industries would also like to make multilayered droplets in precise sizes. This technology should be useful in cosmetics, for example, allowing specific amounts of expensive perfume or anti-aging enzymes to be added to beauty products without unwanted reactions.

Beyond salad dressing
The bubble mixtures the researchers created are called double emulsions. In regular emulsions, two “immiscible” fluids, like oil and vinegar, mix in such a way that one fluid forms droplets in the other. In a double emulsion, a core droplet is surrounded by a second fluid layer, so that the inner fluid is completely shielded from the outer fluid.

Video: Double bubbles Typically, double emulsions are made by shaking two fluids together, like making a vinaigrette, and then shaking that emulsion with a third fluid. Until now, it’s been difficult to manipulate the size of the droplets.

“Double emulsions are a wonderful way to encapsulate things, but normally you can’t make them in a really controlled fashion,” Weitz said.

Weitz and his colleagues instead used a series of small glass tubes, the nose of one inserted in another. As the fluids from the inner tubes flowed into the outer tubes, they formed droplets coated by layers of each fluid.

Super solids
The researchers experimented further with polymers and resins, which could be solidified using light or heat once the droplet had formed. They also used polymers in a solvent and evaporated the excess liquids, producing tiny hollow spheres.

  1. More from TODAY.com
    1. Joan Lunden: 10 things I wish I knew before I was diagnosed with breast cancer

      Doctors found two tumors in my right breast, both triple negative breast cancer, which means it’s more aggressive and fast...

    2. Al Roker, Jay Leno kick off USO comedy tour in Afghanistan
    3. Derek Jeter dismisses 'most eligible bachelor' title: 'No, no, no'
    4. Director: CDC monitoring a 'handful' of people linked to US Ebola case
    5. Joan Lunden on cancer: 'I'm beating this'

Using the polymers, Weitz’s team made permeable, double-layered capsules much like the “liposomes” that transport cargo around our own cells. Weitz’s co-author, Darren Link of Raindance Technologies, speculated that these types of structures might be used to encapsulate whole cells, such as insulin-producing cells. Then, if the shell material were designed just right, it might be possible to slip it into the body without provoking an immune response.

“People have thought for quite some time that cell encapsulation is one route to artificial organs,” Link said.

Many of the potential applications for double emulsions lie a long way off into the future. In the meantime, the new findings have given the Science authors insights into the physics, as well as the poetry, of how fluids move.

“It’s just beautiful,” Link said. “These beautiful shells happening one after another. Who would ever have imagined that you could make such perfect drops in drops? That’s what I like best about it. I think it’s art.”

For more "Mysteries of the Universe" from the journal Science, visit ScienceMag.MSNBC.com.

© 2013 American Association for the Advancement of Science

Discuss:

Discussion comments

,

Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments

More on TODAY.com

  1. Joan Lunden: 10 things I wish I knew before I was diagnosed with breast cancer

    From the moment you hear the words ‘You have breast cancer,’ it’s almost like you’re shot out of a cannon. Here are 10 things I wish I knew before I was diagnosed.

    10/1/2014 10:52:45 AM +00:00 2014-10-01T10:52:45
  2. Want to help? A guide to breast cancer charities

    In the United States an estimated 296,000 women and 2,240 men will be diagnosed with breast cancer this year and almost 40,000 women and 410 men will die of the disease. That's one death every 14 minutes, according to the National Breast Cancer Coalition.

    10/1/2014 10:45:11 AM +00:00 2014-10-01T10:45:11
  3. TODAY
Exclusive
  1. TODAY

    Derek Jeter dismisses 'most eligible bachelor' title: 'No, no, no'

    10/1/2014 11:43:39 AM +00:00 2014-10-01T11:43:39
  1. TODAY

    Al, Jay Leno kick off USO comedy tour in Afghanistan

    10/1/2014 11:00:13 AM +00:00 2014-10-01T11:00:13
  1. Samantha Okazaki / TODAY

    video Joan Lunden tells Hoda she’s ‘beating’ cancer; talks to women fighting cancer on the plaza

    10/1/2014 2:05:08 PM +00:00 2014-10-01T14:05:08