Citric acid coated CoFe2O4 nanoparticles transformed through rapid mechanochemical ligand exchange for efficient magnetic hyperthermia applications

We report the hydrothermal synthesis of uniform size ( 6 nm) oleic acid capped CoFe2O4 (OA-CoFe2O4 ) nanoparticles. These OA-CoFe2O4 nanoparticles were initially hydrophobic and not dispersible in water which were transformed into hydrophilic nanoparticles by modifying their surface with citric acid using a rapid mechanochemical ligand exchange process, which makes CoFe2O4 nanoparticles stable colloidal solution in water. The synthesized citric acid coated CoFe2O4 (CA-CoFe2O4 ) nanoparticles show a high enough and stable zeta potential over 120 days. CA-CoFe2O4 nanoparticles exhibited high biocompatibility under in vitro cell studies. The specific absorption rate (SAR) of the CA-CoFe2O4 nanoparticles was measured by induction heating studies. Upon the exposure of AC external magnetic field, the viability of cancer cells was reduced considerably, suggesting efficient potentiality of these CA-CoFe2O4 nanoparticles for Magnetic Hyperthermia Applications. Present mechanochemical ligand exchange method is proposed as an efficient method for large scale production of biocompatible and water dispersible magnetic oxide nanoparticles for Magnetic Hyperthermia Applications.