Magnetic nanoparticles for nanomedicine applications

• Coloquios

J. Albino Aguiar

Dto Física, Universidade Federal de Pernambuco

Jueves 24/10/2013, 14 hs
Aula Seminario, 2do piso, Pabellón I 

In the recent years, superparamagnetic nanoparticles have been widely used in biology and medicine for different purposes, such as protein and enzyme immobilization, bio-separation, immunoassays, hyperthermia, drug delivery, magnetically enhanced transfection, tissue engineering and MRI. Typically, for biomedical purposes, MNPs are often surface-coated in order to improve their stability and biocompatibility, and to achieve hydrophilicity and conjugating capability. Several coating materials have been used to modify the surface chemistry of the MNPs, including organic polymers (e.g. dextran, chitosan, polyethylene glycol), organic surfactants (e.g. sodium oleate and dodecylamine), inorganic metals (e.g. gold), inorganic oxides (e.g. silica and carbon) and bioactive molecules and structures (e.g. liposomes, peptides and ligands/receptors).

Magnetic nanoparticles (MNPs) can be manipulated under the influence of an external magnetic field. They are usually composed of magnetic elements, such as iron, nickel, cobalt and their respective oxides. In contrast to bulk magnetic materials whose magnetic properties are influenced by the thermal motion between magnetic domains, magnetic nanoparticles show single magnetic domains with all the spins aligned. There is no magnetization interference between domain walls in the MNPs as in the case of bulk materials. Therefore, due to their size, MNPs exhibit different electrical, chemical, magnetic and optical properties than in bulk size.

Iron oxides, such as magnetite (Fe₃O₄), are commonly used for the synthesis of magnetic nanoparticle. They present stable magnetic response, are biodegradable, biocompatible, and present superparamagnetic effects on magnetic resonance imaging (MRI).

In this talk we will present result on the preparation, structural, microstructural and magnetic characterization as well as on the application of magnetic uncoated and fucan-coated and nanoparticles for enzyme immobilization and cancer treatment.