MRI-Guided Nanoparticles Kill Tumors

Nanoparticle research described last week at the annual meeting of the American Association of Physicists in Medicine could revolutionize breast-cancer treatment.

At the meeting, which was in Philadelphia, Xuanfeng Ding, MS, a graduate student at Wake Forest University in North Carolina, presented his research on multiwalled carbon nanotubes (MWCNTs) containing iron. Ding and his colleagues injected the MWCNTs into breast tumors in mice, tracking them with MRI (thanks to the iron), then exposing them to near-infrared laser light. The MWCNTs absorb the laser energy, turning it into heat. The laser-induced thermal therapy (LITT) ablated the tumors.

“This could change the field,” Franklin Epstein, MD, told Medscape Medical News. Dr. Epstein is chief of the Division of Neurosurgery at Audie L. Murphy Memorial Hospital in San Antonio. He is not affiliated with the study.

Dr. Epstein said the “Holy Grail” of neurosurgeons is to find an agent that lights up both in MRI and in the operating room. “These nanoparticles seem to fit that bill, based upon preliminary studies,” he said.

Ding explained to Medscape Medical News that “the idea of this study is to use iron-containing MWCNTs to easily locate these nanoparticles in MRI and aim these particles into the tumor … then fire the laser.”

On mice, it seems to work well. “Clinical practice is definitely our next step,” Ding said. “The only problem will be the toxicity of the nanoparticles.”

Ding said more than 97 percent of the weight of the tiny tubes is carbon, which is not toxic.

“In our experiments, these cleaned MWCNTs don’t show any side effects in our mice at all,” he said. “Will the iron particle be released from the nanotubes after a very long time … [and] have long-term side effects on animals or humans? That is what our biology group is working on. We will have the result soon.”

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