A new method to monitor chemotherapy concentrations could offer a more effective way to keep patient treatments within a crucial therapeutic window, researchers say.
With new advances in medicine happening daily, there’s still plenty of guesswork when it comes to administering chemotherapy to cancer patients. Too high a dose can result in killing healthy tissue and cells, triggering more side effects, or even death. Too low a dose may stun, rather than kill, cancer cells, allowing them to come back, in many cases, much stronger and deadlier.
Researchers created a process based around magnetic particle imaging (MPI) that uses superparamagnetic nanoparticles as the contrast agent and the sole signal source to monitor drug release in the body at the site of the tumor.
“It’s noninvasive and could give doctors an immediate quantitative visualization of how the drug is being distributed anywhere in the body,” says Bryan Smith, associate professor of biomedical engineering at Michigan State University.
“With MPI, doctors in the future could see how much drug is going directly to the tumor and then adjust amounts given on the fly; conversely, if toxicity is a concern, it can provide a view of the liver, spleen, or kidneys as well to minimize side effects. That way, they could precisely ensure each patient remains within the therapeutic window.”
Smith and colleagues used mouse models to pair the superparamagnetic nanoparticle system with Doxorubicin, a commonly used chemotherapy drug. The results, published in NanoLetters, show that the nanocomposite combination serves as a drug delivery system as well as an MPI tracer.
MPI, a new imaging technology, is faster than traditional magnetic resonance imaging (MRI) and has near-infinite contrast. When combined with the nanocomposite, it can illuminate drug delivery rates within tumors hidden deep within the body.
As the nanocomposite degrades, it begins to release Doxorubicin in the tumor. Simultaneously, the iron oxide nanocluster begins to disassemble, which triggers the MPI signal changes. The process will allow doctors to see more precisely how much medicine is reaching the tumor at any depth, Smith says.
“We showed that the MPI signal changes are linearly correlated with the release of Doxorubicin with near 100% accuracy,” he says.
“This key concept enabled our MPI innovation to monitor drug release. Our translational strategy of using a biocompatible polymer-coated iron oxide nanocomposite will be promising in future clinical use.”
Smith has filed a provisional patent for the process. In addition, the individual components of the nanocomposite have already earned FDA approval for use in human medicine. This should help speed FDA approval for the new monitoring method.
As the process moves toward clinical trials, which could potentially begin within seven years, Smith’s team will begin testing multicolor MPI to further enhance the process’s quantitative capabilities, as well as drugs other than Doxorubicin, he says.
Source: Michigan State University
