Iron oxide nanoparticles monitor cancer drug release in real time

Iron oxide nanoparticles allow fluorescent imaging in real time.--Courtesy of UNSW

Researchers at the University of New South Wales have developed iron oxide nanoparticles capable of both delivering cancer drugs and precisely measuring their release in real time.

The UNSW team attached the cancer drug doxorubicin to a polymer shell with an iron oxide core, which were readily taken up by both breast and lung cancer cells. The nanoparticles had a controlled-release mechanism that allowed them to expel the drug into the cells because of the acidic environment.

Most intriguing, though, was the iron oxide's compatibility with fluorescence, which not only proved that the drug had been delivered but also allowed real-time monitoring during the release. To measure the release, the team used for the first time fluorescence lifetime imaging microscopy, which produces an image as fluorescent material decays over time. In the in vitro study, the real-time results showed "a clear increase of native DOX with time," according to an abstract published in the journal ACS Nano.

"Usually, the drug release is determined using model experiments on the lab bench, but not in the cells," UNSW researcher Cyrille Boyer said in a statement. "This is significant as it allows us to determine the kinetic movement of drug release in a true biological environment."

The next step, Boyer said, will be to move to in vivo studies.

- here's the UNSW report
- and here's the ACS Nano abstract