The researchers have revealed that their approach produces droplets that are much smaller than a human cell, and can 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. We have a water droplet inside of an oil droplet, in water," Nature magazine quoted Timothy Deming, professor and chair of the UCLA Department of Bioengineering and a member of both the California NanoSystems Institute (CNSI) at UCLA and UCLA's Jonsson Cancer Center, as saying.
"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. We have demonstrated we can make these emulsions that are stable in this size range, which no one has ever been able to do before. These double nanoemulsions are generally hard to form and very unstable, but ours are very stable," Deming added.
The researchers point out that emulsions are droplets of one liquid in another liquid, a major success because the two liquids do not mix.
"This gives us a new tool, a new material, for drug delivery and anticancer applications," said Thomas G. Mason, a UCLA associate professor of chemistry and physics who has been leading research on nanoemulsions since he joined UCLA five years ago.
In the study report explaining the implications of this research, Deming said: "If we have water-soluble drugs, we can load them inside. If we have water-insoluble drugs, we can load them inside as well. We can deliver them simultaneously."
Mason added: "Here, you effectively combine both types of drug molecules in the same delivery package. This approach could be used for a combination therapy where you want to deliver two drugs simultaneously at a fixed ratio into the same location."
According to the scientists, it might be possible to insert a pharmaceutical inside a droplet and inject the droplet inside a cell.
The researchers are currently trying to determine whether such droplets can release their cargo inside a cell.
"We're working on it. There's a pretty clear path on how to do that. There are still challenges for drug delivery, but we have demonstrated the key first step, that we can make these double emulsions that are stable in this size range," said Deming, who designs and engineers molecules.
Pointing out that the cargo could be a protein toxin that helps to kill the cell, the researchers have revealed that one of the uses of their approach could be to involve an anticancer drug in the oil and a toxin-protein in the water - two molecules trying to kill the cell simultaneously.
While a cell can develop resistance to a single drug, they believe that the combination approach can be more effective.
Deming and Mason, however, insist that there are likely many years of research before cancer patients could be treated in such a manner.
"We'll have to do a lot of fine-tuning, but this approach has a lot of advantages. The size of these is a big advantage. We have discovered unique molecular features that can stabilize double emulsions. These are promising, but it's early on, and there are many ways these can fail. But we should at least learn how to make better drug-delivery vehicles," Deming said.
The researchers say that their future studies will determine whether the droplets can harmlessly enter cells and release their cargo.
Apart from medical purposes, the researchers say that the nanodroplets produced through their method can also be used in cosmetics, soaps and shampoos.