In this study, Bulgarian researchers investigated the potential of mixed ferrite nanoparticles with the structural formula Me1?xZnxFe2O4 (Me = Co, Ni, Cu, Mn) for cancer therapy. Their results were published in The European Physical Journal B.
Magnetic nanoparticles (MNPs) can be delivered close to tumor cells and activated using alternating magnetic fields.
This new type of therapy, called magnetic hyperthermia therapy, can be an effective cancer therapy if these MNPs are absorbed well by tumor cells but not by healthy cells -- a function measured as a cell's specific absorption rate (SAR).
In their previous studies, the researchers explored the characteristics of MNPs made of an iron oxide material known as a ferrite.
Doping ferrites, which involves the addition of small quantities of copper, nickel, manganese or cobalt atoms, is believed to affect the SAR of MNPs.
Using MNPs doped with these minerals, the researchers investigated the effectiveness of magnetic hyperthermia in tumor-bearing mice and cultured tumor cells using two distinct heating methods.
These heating methods differed in terms of how heat was generated in the particles, i.e., via direct or indirect coupling between the magnetic field and the magnetic moment of the particles.
The researchers found that the tumor cells' SAR of destructive heat depends on the diameter of the MNPs and the composition of the magnetic material used to deliver the heat.
As particle diameter increased, SAR also increased, so long as the level of doping and the diameter of the MNPs did not exceed a set maximum value (e.g., 14 nanometers for cobalt doping and 16 nanometers for copper).
Based on these findings, the researchers concluded that magnetic hyperthermia therapy is a viable and tunable new therapy that can kill cancer tumors.
Apostolov A, Apostolova I, Wesselinowa J. SPECIFIC ABSORPTION RATE IN ZN-DOTED FERRITES FOR SELF-CONTROLLED MAGNETIC HYPERTHERMIA. The European Physical Journal B. 11 March 2019;92(3). DOI: 10.1140/epjb/e2019-90567-2