Magnetic hyperthermia, an auxiliary tool in cancer treatments

July 8, 2015

Hyperthermia (increase in body temperature) has been used for centuries to combat tumours and reduce their effects. The aim of research by the physicist Eneko Garaio is hyperthermia but using a different system (magnetic nanoparticles) to increase body temperature. These nanoparticles absorb energy from magnetic fields and convert it into heat which is used to raise the temperature in tumours and combat them. A paper on this subject by Garaio and other authors, published in 2014 in the journal Measurement Science and Technology, has recently received the Outstanding Paper Award.

Back in the 1990s, it was discovered that under the action of alternating magnetic fields, absorbed a large quantity of energy. Out of that discovery emerged magnetic , an experimental cancer therapy in which magnetic particles strategically placed in tumours are turned into a source. Nanoparticles emit the energy they absorb from the alternating as heat, which is applied to them externally, causing the temperature in the tumours to rise.

According to Garaio, this system offers various advantages: "Firstly, the magnetic fields used are not harmful for the body. In other words, they produce no heat so they do not affect the healthy parts of the body. Secondly, nanoparticles can be surrounded by ligands. The particles tend to be iron oxide while the ligand is made up of a layer produced by means of organic molecules. This system enables the nanoparticles to stick to the cells without affecting the healthy cells".

There are various methods of raising the temperature, and hyperthermia treatments are classified on the basis of the technique used. In radiofrequency hyperthermia, for example, electric currents induced by electromagnetic waves are used to raise the temperature of tumours, with antennas concentrating the heat in the tumours. The placing of these antennas beside the tumours is done by means of surgery. In ultrasound hyperthermia, the heating is carried out by means of vibrations; in laser hyperthermia, by contrast, infrared laser is used to excite gold or silver nanoparticles placed beside the tumours to heat the .

Hyperthermia, an old technique with new applications

According to Garaio, the most important result of his research is this: "We manufactured a tool to measure the specific nanoparticle absorption rate; we then built various models to calculate the specific absorption rate and to find out how the shape, material and ligands of the change". As regards lab tests, "we induced necrosis in the livers of three mice without causing any damage to the healthy cells of these organs," pointed out the researcher.

Doctors were aware of the effectiveness of heat to combat tumours over a thousand years ago, and about 200 years ago they induced fever in their patients so that the heat would combat the tumours. "Basically, that is what hyperthermia is," explained Garaio. "But the heat mustn't be administered in just any part of the body nor in just any way. It must only be applied to the tumours at a temperature ranging between 41 and 46 °C. That is the temperature range in which magnetic hyperthermia is the most effective," said the author of the thesis.

Explore further: Flower-like magnetic nanoparticles target difficult tumors

More information: "Specific absorption rate dependence on temperature in magnetic field hyperthermia measured by dynamic hysteresis losses (ac magnetometry)." Nanotechnology. 2015 Jan 9;26(1):015704. DOI: 10.1088/0957-4484/26/1/015704

Related Stories

Flower-like magnetic nanoparticles target difficult tumors

March 3, 2015

Thanks to the work of an interdisciplinary team of researchers at the Dartmouth Center of Nanotechnology Excellence, funded by the National Institutes of Health, the next-generation magnetic nanoparticles (MNPs) may soon ...

Nanoparticles to kill cancer cells with heat

June 17, 2015

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 ...

Hot nanoparticles for cancer treatments

March 24, 2014

Nanoparticles have a great deal of potential in medicine: for diagnostics, as a vehicle for active substances or a tool to kill off tumours using heat. ETH Zurich researchers have now developed particles that are relatively ...

Recommended for you

Nanotube fiber antennas as capable as copper

October 23, 2017

Fibers made of carbon nanotubes configured as wireless antennas can be as good as copper antennas but 20 times lighter, according to Rice University researchers. The antennas may offer practical advantages for aerospace applications ...

Resistive memory components the computer industry can't resist

October 23, 2017

Make way for some new memsistors. For years, the computer industry has sought memory technologies with higher endurance, lower cost, and better energy efficiency than commercial flash memories. Now, an international collaboration ...

Taming 'wild' electrons in graphene

October 23, 2017

Graphene - a one-atom-thick layer of the stuff in pencils - is a better conductor than copper and is very promising for electronic devices, but with one catch: Electrons that move through it can't be stopped.

Breakthrough in ultra-fast data processing at nanoscale

October 20, 2017

A research team from the National University of Singapore has recently invented a novel "converter" that can harness the speed and small size of plasmons for high frequency data processing and transmission in nanoelectronics.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.