Magnetic nanoparticles if absorbed by tumor cells can heat them up and destroy them. This effect can be activated by an alternating magnetic field. The results of this study are published in the EPJ B journal.
Unfortunately, cancer isn't simply a single disease, and some types, like pancreas, brain or liver tumors, are still difficult to treat with chemotherapy, radiation therapy or surgery, leading to low survival rates for patients. Thankfully, new therapies are emerging, like therapeutic hyperthermia, which heats tumors by firing nanoparticles into tumor cells. In a new study published in EPJ B, Angl Apostolova from the University of Architecture, Civil Engineering and Geodesy in Sofia, Bulgaria and colleagues show that tumor cells' specific absorption rate of destructive heat depends on the diameter of the nanoparticles and the composition of the magnetic material used to deliver the heat to the tumor.
Magnetic nanoparticles delivered close to the tumor cells are activated using alternating magnetic fields. Hyperthermia therapy is effective if the nanoparticles are absorbed well by the tumor cells but not by cells in healthy tissue. Therefore, its effectiveness depends on the specific absorption rate. Bulgarian scientists have studied several nanoparticles made of an iron oxide material called ferrite, to which are added small quantities of copper, nickel, manganese or cobalt atoms--a method called dopping.
The authors show that the tumor absorption rate greatly depends on the diameter of the nanoparticles. Surprisingly, the absorption rate increases as particle diameter increases, as long as the level of doping of the material is sufficiently high and the diameter doesn't exceed a set maximum value (max. 14 nanometres for cobalt doping, 16 nm for copper).