Tailored nanoparticles for tumour therapy

Gd doped iron-oxide nanoparticles were developed for use in tumour therapy via magnetic fluid hyperthermia (MFH). The effect of the Gd ³⁺ dopant on the particle size and magnetic properties was investigated. The final particle composition varied from Gd ₀₀₁Fe _0.99O ₄ to Gd _0.04Fe _2.96O ₄ as determined by Inductively coupled plasma atomic emission spectroscopy (ICP-AES). TEM image analysis showed the average magnetic core diameters to be 12nm and 33nm for the lowest and highest Gd levels respectively. The specific power adsorption rate (SAR) determined with a field strength of 246 Oe and 52 kHz had a maximum of 38Wg ^?1 [Fe] for the Gd _0.03Fe _2.97O ₄ sample. This value is about 4 times higher than the reported SAR values for Fe ₃O ₄. The potential for in vivo tumour therapy was investigated using a mouse model. The mouse models treated with Gd _0.02Fe _0.98O ₄ displayed much slower tumour growth after the first treatment cycle, the tumour had increased its mass by 25% after 7 days post treatment compared to a 79% mass increase over the same period for those models treated with standard iron-oxide or saline solution. After a second treatment cycle the mouse treated with Gd _0.02Fe _0.98O ₁ showed complete tumour regression with no tumour found for at least 5 days post treatment.