jp510937r_si_001.pdf (215.65 kB)
High Specific Absorption Rate and Transverse Relaxivity Effects in Manganese Ferrite Nanoparticles Obtained by an Electrochemical Route
journal contribution
posted on 2015-03-26, 00:00 authored by Eva Mazarío, Jorge Sánchez-Marcos, Nieves Menéndez, Magdalena Cañete, Alvaro Mayoral, Sara Rivera-Fernández, Jesús M. de la Fuente, Pilar HerrastiSuperparamagnetic
iron oxide-based nanoparticles (SPIONS) have
attracted an enormous amount of attention for their potential use
in biomedical applications, due to their good biocompatibility and
low toxicity. The current study considers citric acid-conjugated manganese
ferrite and its synergy to be used in MRI and in hyperthermia treatment,
thus showing theragnostic applications. High colloidal stability was
obtained with this functionalization. SPIONS with superparamagnetic
behavior of crystal sizes of approximately 20 nm were obtained via
an electrochemical synthesis method. One of the highest specific absorption
rate (SAR) values was achieved in this work (1661 W g–1), under a magnetic field of 30 mT at 717 kHz frequency, compared
with other magnetic ferrites in the literature. These nanoparticles
dissipate heat through Néel relaxation and, together with the
high SAR value obtained, indicate an excellent material for hyperthermia
treatment of cancer. In addition, these nanoparticles exhibit transverse
relaxivity behavior, with an r2 value
of 394 mM–1 s–1, i.e., at least
two times higher than the value of a commercial magnetic contrast
agent based on iron oxides. Finally, no toxicity effects of these
nanoparticles are evidenced; as a result, these nanoparticles are
appropriate for in vivo application.