RESUMO
Direct interactions between nanoparticles of Mn-doped magnetite or maghemite (clearly differentiated by Raman spectroscopy) grouped in spherical clusters minimize the effect related to their characteristic magnetic dead layer at the surface. Hence, the clustering process jointly with the manganese doping renders these ferrite nanostructures very attractive as displaying increased saturation magnetization, offering, consequently, outstanding values of the specific absorption rate (SAR) for heat delivery. The whole picture for bio-related applications has been considered, with issues related to magnetic manipulation, colloidal stability, and biocompatibility.
RESUMO
Hybrid nanocomposites based on ferrimagnetic (FiM) Fe3O4 and magnetoelectric antiferromagnetic (AFM) Cr2O3 nanocrystals were synthesized to offer a particular three-dimensional (3D) interface between the two oxides. This interface favours an intermixing process (demonstrated by combining Raman spectroscopy and magnetization measurements) that determines the final magnetic behavior.
RESUMO
This article presents a capable strategy of using hybrid nanostructures to improve the magnetic-based performance jointly with the internalization process into cells, for drug delivery applications. The promising combination stems from the concept of magnetic silica nanostructures, referring to magnetic nanoparticles of transition metal ferrites, coated with a silica (or hydroxyapatite) shell or included in a hollow silica nanostructure, such that they can offer a proper and controlled drug delivery. The synergy effects are brought on considering several characteristics; the magnetic properties of the transition metal ferrites as aggregates, the increased biocompatibility, the reduced toxicity, the porosity, the suitable chemical functionalization of silica and different effects such as local heating based on hyperthermia or other triggering effects for a time-space controlled drug delivery.
