Necrosis of carcinoma cells using Co1-xNixFe2O4 and Ba1-xSrxFe12O19 ferrites under alternating magnetic field

The purpose of this study was to investigate the cell necrosis by the hysteric heating of Co_1-xNi_xFe₂O₄ and Ba_1-xSr_xFe₁₂O₁₉ ferrites under external magnetic field with respect to applications in hyperthermic cancer treatments. Co_1-xNi_xFe₂O₄ and Ba_1-xSr_xFe₁₂O₁₉ ferrites were synthesized by a sol-gel process. Variation of the temperature as a result of hysteresis heating was measured as a function of the exposure time to the external alternating magnetic field at frequencies of 0.1 ∼ 15 MHz. A human squamous cell carcinoma KB cell line was selected to determine the effect of the synthesized ferrites on the destruction of carcinoma cells in vitro using a methylthiazol tetrazolium bromide (MTT) method. When a CoFe₂O₄ disc was placed in 0.2 ml of distilled water, the greatest temperature change (ΔT=29.3°C) was observed. More than half of the malignant carcinoma cells were dead after being exposed to the 7-MHz ac magnetic field for 1 h by CoFe₂O₄ ferrites, while normal cells survived more than 60% of the time.