Citric Acid-Coated Magnetite Nanoparticles. Previous Fundamental Studies to Biomedical Applications

Line to the objectives of the scientific initiation program at UNICAMP, in this work we present partially results of an interdisciplinary and larger project that involves the synthesis, characterization and basic studies of magnetite nanoparticles, as well as cytotoxicity and drug delivery studies on rats. Specifically, citric acid-coated magnetite nanoparticles (Fe3O4) were synthesized by the co-precipitation method. Citric acid shell was employed whit three central objectives: to avoid the nanoparticle aggregation, to ensure a stable dispersion in water, and to guarantee the biocompatibility of the magnetite nanoparticles. Citric acid-coated magnetite nanoparticles (Fe3O4) of mean diameter of 7.2 nm and a standard deviation of σ = 0.25 were synthesized by the co-precipitation method. Citric acid shell was employed whith three central objectives: to avoid the nanoparticle aggregation, to ensure a stable dispersion in water, and to guarantee the biocompatibility of the magnetite nanoparticles. Structural properties of the obtained nanoparticles were characterized by X-diffraction, small angle X-ray scattering and transmission electron microscopy techniques. Magnetic behavior was studied by means of magnetization vs. magnetic field and ZFC-FC curves. Size-dependent magnetic parameters such as anisotropy, magnetic moment per particle, blocking temperature, and dipolar interaction energy were inferred using basic phenomenological approaches. Magnetic and structural results indicate the presence of non-compact cluster and the overall magnetic response is near to the superparamagnetic state.