Superparamagnetic cobalt ferrite nanoparticles as T2 contrast agent in MRI: in vitro study.

Superparamagnetic cobalt ferrite nanoparticles (CoFe2O4) possess favourite advantages for theranostic applications. Most of previous studies reported that CoFe2O4 magnetic nanoparticles (MNPs) are suitable candidates for induction of hyperthermia and transfection agents for drug delivery. The present study synthesized and investigated the potential use of CoFe2O4 as a contrast agent in magnetic resonance imaging (MRI) by using a conventional MRI system. The CoFe2O4 were synthesized using co-precipitation method and characterized by TEM, XRD, FTIR, EDX and VSM techniques. Relaxivities r1 and r2 of CoFe2O4 were then calculated using a 1.5 Tesla clinical magnetic field. The cytotoxicity of CoFe2O4 was evaluated by the MTT assay. Finally, the optimal concentrations of MNPs for MRI uses were calculated through the analysis of T2 weighted imaging cell phantoms. The superparamagnetic CoFe2O4 NPs with an average stable size of 10.45 nm were synthesized. Relaxivity r1,2 calculations resulted in suitable r2 and r2/ r1 with values of 58.6 and 51 that confirmed the size dependency on relaxivity values. The optimal concentration of MNPs for MR image acquisition was calculated as 0.154 mM.
Conclusion: CoFe2O4 synthesized in this study could be considered as a suitable T2 weighted contrast agent because of its high r2/r1 value.