Single and Dual Surfactants Coated Hydrophilic Superparamagnetic Iron Oxide Nanoparticles for Magnetic Fluid Hyperthermia Applications.

Superparamagnetic iron oxide nanoparticles (SPIONs) have found applications in the magnetic fluid hyperthermia (MFH) due to their unique magnetic properties, chemical stability and biocompatibility. However, challenges exist in attaining high heating efficiencies of the SPIONs under the applied alternating magnetic fields below Hergt's biological safety limit. Here, we present synthesis of single surfactant (pyromellitic acid (PMA)/2-aminoterephthalic acid (ATA)) and dual surfactants (PMA-ATA) coated SPIONs via chemical co-precipitation method and characterization to determine their phase purity, surface coatings and particle sizes. The hydrodynamic sizes/zeta potentials values of the SPIONs were determined for studying their water-dispersibility. Finally, the impact of heating on specific absorption rate (SAR) and intrinsic loss of power (ILP) were determined. SPIONs were found to exhibit magnetite phase and particle sizes in the range of 9-10 nm, good water dispersibility with (i) hydrodynamic diameters ranging from 190-304 nm and (ii) zeta potentials ranging from -38 mV to -49 mV. The ATA and PMA-ATA coated SPIONs showed better time-dependent temperature rise that resulted in higher heating efficacies-i.e., SAR and ILP values ranging from 58.6-79.5 W/g and 1.7-2.3 nHm²/Kg, respectively as compared to the PMA coated SPIONs. Thus, ATA and PMA-ATA coated SPIONs were found to be very promising candidates for their usage in MFH applications.