Magnetic fluid hyperthermia (MFH) is a promising new cancer treatment that essentially 'fries' cells inside tumours. The procedure has been used successfully in prostate, liver, and breast tumours. Magnetic nanoparticles (each billionths of a metre in size) are injected into the body intravenously and diffuse selectively into cancerous tissues. Add a high-frequency magnetic field, and the particles heat up, raising the temperature of the tumour cells.
'The entire tumour volume is heated above a threshold treatment temperature - typically 42 degrees Celsius (107.6 degrees Fahrenheit) - for generally 30 minutes,' explains engineering graduate student Monrudee Liangruksa of Virginia Tech.
The outcome? As described today at the American Physical Society Division of Fluid Dynamics (DFD) meeting in Long Beach, CA, when the nanoparticles are heated, cancer cells die with no adverse effects to the surrounding healthy tissue.
To further perfect the technique, Liangruksa and her colleagues explored the effects of different types of magnetic nanoparticles. The most promising varieties, they found, were iron - platinum, magnetite, and maghemite, all of which generate therapeutically useful heating. 'However, we wish to use MFH in humans,' she says, and 'the most biocompatible agents are magnetite and maghemite. Iron - platinum is toxic and vulnerable to oxidation.'