Sending chemotherapy drugs directly to tumors — and away from healthy tissues — is one of the promises of nanotechnology.
Many scientists have focused on developing nanocarriers out of polymers or other protective materials to encapsulate a drug as it travels to its final destination. But little is known about how long the structures last, or what processes might change them. Now, researchers at the University of Delaware have found that it’s important to pay attention to how the nanocarriers are handled.
“Normally, one makes an implicit assumption that when you’ve made a solution of a drug, that you put it in a vial, and that the surface of the vial and the air in the vial, they don’t matter — that they’re inert,” said Millicent Sullivan, a chemical and biomolecular engineer and one of the authors of the latest study.
But that’s not true for nanocarriers. Along with a fellow engineer and polymer scientist, Thomas Epps, she found that up to eight of them would combine — creating much larger capsules — if the solution were gently shaken.
That’s a problem because in the nanoworld, size matters. Sullivan said if the capsules are too small, they’ll pass through to the urine. Too big, and they collect in the spleen.
“How someone shakes and stirs and actually disturbs that contents actually has a large influence on its resulting properties, which then will influence its function,” said Epps.
He said the findings could be used to design appropriate packaging and inform future prescribing rules.