Nanoparticles to kill cancer cells with heat

June 17, 2015 by Chad Boutin
Nanoparticles to kill cancer cells with heat
Iron oxide nanoparticles with a neatly-stacked internal structure (left) need a stronger magnetic field than expected to heat up, while those with a more haphazard arrangement heat up more quickly, even under a weak field. The findings, which run contrary to expectations, could affect which nanoparticles are chosen to treat certain types of cancer. Credit: NIST

Heat may be the key to killing certain types of cancer, and new research from a team including National Institute of Standards and Technology (NIST) scientists has yielded unexpected results that should help optimize the design of magnetic nanoparticles that can be used to deliver heat directly to cancerous tumors.

When combined with other treatments such as radiotherapy or chemotherapy, applied directly to tumors helps increase the effectiveness of those types of treatments, and it reduces the necessary dose of chemicals or radiation.

This is where come in. These balls of iron oxide, just a few tens of nanometers in diameter, heat up when exposed to a powerful magnetic field. Their purpose is to bring heat directly to the tumors. Materials research, performed in part at the NIST Center for Neutron Research (NCNR), revealed magnetic behavior that proved counterintuitive to the scientific team—a finding that will affect which particles are chosen for a particular treatment.

Choosing the right kind of particles is important because, depending on their structure, they deliver a different dose of heat to the cancer. Some heat up quickly at first, while others require a stronger magnetic field to get going but ultimately deliver more heat.

"You want to design your nanoparticles for the kind of cancer you're treating—whether it's localized or spread through the body," says NIST's Cindi Dennis. "The amount of electricity needed to create the field can be 100 kilowatts or more. That costs a lot of money, so we want to help engineer particles that will do the best job."

Although the magnetic field applied for hyperthermia is 100 to 1,000 times weaker that that typically used for MRI imaging, Dennis explains, it's an alternating field (the magnetic polarity switches rapidly), which requires a lot more power.

With colleagues at Johns Hopkins University School of Medicine, the University of Manitoba and in industry, the team studied two kinds of , each of which has a different internal structure. In one, iron-oxide crystals are stacked neatly, like bricks in a wall; in the other, the arrangement is more haphazard, like balls in a playpen. While subjecting both types to an alternating magnetic field, the team discovered that the neatly-stacked ones needed a stronger field than expected to heat up, while the haphazard particles got hot more quickly, even when the field was still weak.

It took a trip to the NCNR to figure out why these nanoparticles acted strangely. The neutron experiments showed regions of different sizes and shapes in the particles. Within each region, the so-called magnetic moments are uniform and point in the same direction. But the regions themselves did not align with each other. This unexpected behavior among regions, it turns out, profoundly affects the nanoparticles' response to a ."

Materials often behave unexpectedly on the nanoscale, and here we have another example of that," Dennis says. "We expect it will help design better cancer treatments. A localized cancer could be treated with nanoparticles that give out lots of heat right away because the field can be focused on a small region."

Explore further: Flower-like magnetic nanoparticles target difficult tumors

More information: "Internal magnetic structure of nanoparticles dominates time-dependent relaxation processes in a magnetic field." Advanced Functional Materials. Published online June 2, 2015. DOI: 10.1002/adfm.201500405

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5 / 5 (1) Jun 17, 2015
So, how are the nanoparticles expelled after their task is done? Or does the person need to beware of high magnetic charges from then on because the particles are still in there and capable of creating heat?
not rated yet Jun 17, 2015
I'm not entirely sure from reading their article what their magnet set up is. But I bet if they build a giant 3-phase motor winding and used 3-phase AC it would be very effective and efficient. Instead of switching polarity of a DC system repeatedly.
1 / 5 (2) Jun 17, 2015

So, how are the nanoparticles expelled after their task is done? Or does the person need to beware of high magnetic charges from then on because the particles are still in there and capable of creating heat?
I don't understand - are you suggesting that researchers would design these things with hazardous side effects and that it would be up to the patient to avoid these side effects?
1 / 5 (2) Jun 18, 2015
So, cancer IS caused by the flu vaccine (the fever invoked by the illness is carcinogenic).
5 / 5 (1) Jun 18, 2015
So, cancer IS caused by the flu vaccine (the fever invoked by the illness is carcinogenic).

Non sequitur fur sure.

The various flu vaccines MAY have some effects on existing cancers, it may also have a considerable effects on cancers ... But there is a chance that some of the various flu vaccines may also have a net positive effect on cancers and (of course) those ailments and diseases that some flu vaccines target as well as the general health.

Anonym: Your specific point may be away from the intended mark: that flu vaccines are "bad", However there is certainly a possible concern that flu vaccines might have a net negative effect on "cancer" ... or even the possibly small chance that flu vaccines may actually cause some types of cancers ...

A deep statistical look into this would probably be a good idea. Perhaps one could pose this question to ?

It may not be just the heat, it may also be the humility.
1 / 5 (4) Jun 19, 2015
Cancer can be treated with proper nutrition and faith. The rest is business.
5 / 5 (2) Jun 20, 2015
Cancer can be treated with proper nutrition and faith. The rest is business.

So you've found a cure/better treatment for cancer and its proper nutrition and "faith"? Wow. You need to contact all the cancer Institutes and researchers and medical publications and the Nobel prize committee and share your papers and experiments with them and prepare to be famous and known worldwide and to have your name go down in human history.

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