Specific heating power of fatty acid and phospholipid stabilized magnetic fluids in an alternating magnetic field

Magnetic fluids (MFs) with a similar narrow size distribution of the iron oxide core were stabilized with lauric acid (MF 1), oleate (MF 2) or, after dialysis in the presence of liposomes, with phospholipid molecules (MF 3 and MF 4, respectively). The hydrodynamic sizes of the MF 1 and MF 3 were half those found for MF 2 and MF 4. The MFs were exposed to inductive heating in an alternating magnetic field at a frequency of 200 kHz and a maximum magnetic field strength of 3.8 kA m(-1). Specific absorption rates (SAR) of 294 +/- 42 (MF 1), 214 +/- 16 (MF 2), 297 +/- 13 (MF 3) and 213 +/- 6 W g(-1) Fe (MF 4) were obtained. The data for MF 2 and MF 4 were identical to those found for the commercially available ferucarbotran. The biomedical relevance of the phospholipid-coated MFs is briefly discussed.