Magnetic Hyperthermia

Subject – Science and Tech

Context – Hot magnets that kill cancer cells while sparing healthy ones.

Concept –

Magnetic hyperthermia — generating heat in magnetic nanoparticles by applying alternating magnetic fields on them — has been an area of research in cancer therapy since the 1990s.
The goal is to burn away cancer cells. Conventional treatments such as chemotherapy do that, but they also kill adjoining healthy cells, with severe side effects.
Magnetocaloric materials — heat up when inside a magnetic field and cool when pulled out.
The use of magnets in cancer treatment — ‘magnetic hyperthermia’ — has been explored earlier through clinical trials in China, Europe and the US.
In conventional magnetic hyperthermia, magnetic nanoparticles are subjected to alternating magnetic fields (of a few gauss), which produces heat due to magnetic relaxation losses. Usually, the temperature required to kill tumor cells is 40-46 degree C. However, the drawback here is the lack of temperature control, which may damage healthy cells and cause side effects like increased blood pressure.
Magnetocaloric materials, on the other hand, provide controlled and self-regulated heating. Moreover, they cool down as soon as the magnetic field is removed, unlike the magnetic nanoparticles, which remain overheated even after the removal of the magnetic field.
‘Curie temperature’ – the point at which magnetic materials undergo a change in their magnetic properties.
The minimum temperature required for cancer therapy is 42°C.