Oxidative Precipitation Synthesis of Calcium-Doped Manganese Ferrite Nanoparticles for Magnetic Hyperthermia

Superparamagnetic nanoparticles are of high interest for therapeutic applications. In this work, nanoparticles of calcium-doped manganese ferrites (CaxMn1-xFe2O4) functionalized with citrate were synthesized through thermally assisted oxidative precipitation in aqueous media. The method provided well dispersed aqueous suspensions of nanoparticles through a one-pot synthesis, in which the temperature and Ca/Mn ratio were found to influence the particles microstructure and morphology. Consequently, changes were obtained in the optical and magnetic properties that were studied through UV-Vis absorption and SQUID, respectively. XRD and Raman spectroscopy studies were carried out to assess the microstructural changes associated with stoichiometry of the particles, and the stability in physiological pH was studied through DLS. The nanoparticles displayed high values of magnetization and heating efficiency for several alternating magnetic field conditions, compatible with biological applications. Hereby, the employed method provides a promising strategy for the development of particles with adequate properties for magnetic hyperthermia applications, such as drug delivery and cancer therapy.

Automated summary

In this study, citrate-functionalized calcium-doped manganese ferrite nanoparticles were synthesized through thermally assisted oxidative precipitation. The nanoparticles showed good dispersibility and their microstructure and morphology could be controlled by adjusting the temperature and Ca/Mn ratio. The optical and magnetic properties of the nanoparticles were studied using UV-Vis absorption and SQUID, respectively. XRD and Raman spectroscopy were used to analyze the microstructural changes associated with particle stoichiometry, and the stability of the nanoparticles in physiological pH was tested using DLS. The nanoparticles exhibited high magnetization and heating efficiency under alternating magnetic field conditions, making them suitable for biomedical applications.