Heating Tumors to Death using Functionalized Fe

Application of Magnetic Nanoparticles (MN) has emerged as a potential mode of hyperthermia, a modality for cancer therapy, in which temperature of a tumor is increased beyond physiological temperature up to 40-43 °C. We have prepared Fe 3 O 4 magnetic nanoparticles (Fe 3 O 4 -MN), which were surface-functionalized with polyethylene glycol (Fe 3 O 4 -PEG-MN) and oleic acid (Fe 3 O 4 -OAMN) to make them water and lipid soluble, respectively; as well as to control their size. The particle sizes for Fe 3 O 4 -MN, Fe 3 O 4 -OA-MN and Fe 3 O 4 -PEG-MN were found to be 12, 6 and 8 nm, respectively. Under induction heating conditions, these MN preparations could achieve hyperthermic temperature. Interestingly, Fe 3 O 4 -OA-MN showed higher cytotoxicity in human breast cancer cells as compared to Fe 3 O 4 -MN and Fe 3 O 4 -PEG-MN, which was further enhanced when MN treated cells were subjected to induction heating. Fig. 1: Schematic outline of application of Magnetic Nanoparticles in Cancer Therapy Application of hyperthermia to tumor tissue is done in two ways: (i) applying external source of heat (e.g. water bath, microwave, ultrasound, infrared sauna) which is also called ‘external or extracellular hyperthermia’ and (ii) delivering MN inside the cancer cells followed by application of alternating current (AC) field, which would increase the temperature of tumor mass. The latter approach is known as ‘intracellular hyperthermia’ (Fig. 2). Cell