Magnetic Nanoparticles for Detecting Cancer

Researchers have designed highly magnetized nanoparticles based on metallic iron that could soon be used in a non-invasive therapy for cancer in which treatment would begin at the time of detection.

"We envision a potential for these materials to combine both detection and treatment into a single process,” said Everett E. Carpenter, Ph.D., an assistant professor of chemistry at Virginia Commonwealth University (VCU; Richmond, USA). Dr. Carpenter and coworkers are trying to determine how to best construct the core-shell structure and figure out which shell compounds are most suited for biomedical applications such as magnetodynamic therapy (MDT), or as magnetic resonance imaging (MRI) contrast enhancement agents.

According to Dr. Carpenter, in the future it may be possible for a patient to be screened for breast cancer using MRI methods with engineered enhanced ferrites as the MRI contrast agent. He said if a tumor is identified, the clinician could then increase the power to the MRI coils and localized heating would destroy the tumor site without damaging the surrounding healthy cells.

Another promising biomedical tool is MDT, which utilizes magnetic nanoparticles that are combined with the radiofrequency waves of MRI. This coupling changes the radiofrequency into heat energy that kills the cancer cells. European researchers studying MDT have shown that nanoparticles are able to target tumor cells. Dr. Carpenter reported that because the nanoparticles target tumor cells and are substantially smaller than human cells, only the very few tumor cells next to the nanoparticles are killed, which greatly minimizes damage to healthy cells.

Enhanced ferrites are a group of ferrites that are specifically modified to have enhanced magnetic or electrical characteristics and are created through the use of core-shell morphology. According to Dr. Carpenter, with this approach the core can be a highly magnetic material such as iron or iron alloys, whereas the shell can be a mixed metal ferrite with customized resistivity. Dr. Carpenter said that the high magnetization of the enhanced ferrite nanoparticles may potentially improve the absorption of the radiofrequency waves, thereby providing optimal identification of tumor sties and the use of less MRI contrast agents.

In 2002, Carpenter created a new material based on metallic iron. He said the magnetic power of the iron nanoparticles he invented is 10 times greater than that of the currently available iron oxide nanoparticles, which translates to a considerable decrease in the amount of iron needed for imaging or therapy.




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