November 26, 2010
(Ivanhoe Newswire) -- Using a healthier hyperthermia, Virginia Tech engineering researchers and a colleague from India unveiled a new method to target and destroy cancerous cells without using chemotherapy.
The cancer treatment uses hyperthermia to elevate the temperature of tumor cells, while keeping the surrounding healthy tissue at a lower degree of body heat. The investigators used both in vitro and in vivo experiments to confirm their findings.Ishwar Puri, professor and head of the engineering science and mechanics department explained that to further perfect the technique they used ferrofluids to induce the hyperthermia. A ferrofluid is a liquid that becomes strongly magnetized in the presence of a magnetic field. The magnetic nanoparticles are suspended in the non-polar state.
"These fluids can then be magnetically targeted to cancerous tissues after intravenous application," Puri was quoted as saying. "The magnetic nanoparticles, each billionths of a meter in size, seep into the tissue of the tumor cell due to the high permeability of these vessels."
The magnetic nanoparticles are heated by exposing the tumor to a high frequency alternating magnetic field, causing the tissue's death by heating. This process is called magnetic fluid hyperthermia and they have nicknamed it thermotherapy. Temperatures in the range of 41 to 45 degrees Celsius are enough to slow or stop the growth of cancerous tissue, but without the process of magnetic fluid hyperthermia, these temperatures also destroy healthy cells.
"The ideal hyperthermia treatment sufficiently increases the temperature of the tumor cells for about 30 minutes while maintaining the healthy tissue temperature below 41 degrees Celsius," Puri said. "Our ferrofluid-based thermotherapy can be also accomplished through thermoablation, which typically heats tissues up to 56 degrees C to cause their death, coagulation, or carbonization by exposure to a noninvasive radio frequency, alternating current magnetic field. Local heat transfer from the nanoparticles increases the tissue temperature and ruptures the cell membranes."
SOURCE: The 63rd annual meeting of the American Physical Society held in Long Beach, Calif. On November 23, 2010