Delivery method uses a cancer cell's power source to trigger drug release

A nanoparticle designed to release a cancer drug using ATP as a trigger--Courtesy of NC State

Every living cell stores or spends its energy in the form of adenosine triphosphate, or ATP, which has historically been known as the "molecular unit of currency." And using this molecule as a targeting mechanism for cancer drugs, scientists in North Carolina have developed a way to trigger the release of chemotherapy within the offending cells.

The researchers at North Carolina State University and the University of North Carolina-Chapel Hill published the paper in the journal Nature Communications, which shows that nanoparticles targeted to enter a cancer cell and release a common drug where ATP is most prevalent was 3.6 times more effective against breast cancer cells than other delivery methods.

The round nanoparticles are coated with a shell that contains hyaluronic acid, which targets cancer cells and incites the cell to absorb the entire nanoparticle. Once inside, though, the drug, in this case doxorubicin, is still encased in a nanoparticle, so the trick is to trigger its release.

To do this, the team also embedded DNA molecules into the nanoparticle that are designed to unravel when they come into contact with higher ATP levels, according to a report. Since these levels are highest inside the cell, they ostensibly will not be released outside the cell, where the cancer drug could then do damage to healthy cells.

"This is a proof of concept, but we've demonstrated there is now a new tool for introducing anti-cancer drugs directly into cancer cells--and that should make drug treatments significantly more effective," senior author Zhen Gu said in a statement. "… We also believe that we'll be able to make the technique more targeted by manipulating ATP levels in specific areas."

And according to Gu's colleague Ran Mo, lead author of the paper, "(t)his is the first time ATP has been used as a molecular trigger for controlled release of anti-cancer drugs, both in vitro and in vivo."

- here's the NC State announcement