Biocompatible gum arabic coated iron oxide magnetic nanoparticles for potential drug delivery

PAMELA L. AZCONA; M. FERNANDA HORST; MARIELA A. AGOTEGARAY; VERÓNICA L. LASSALLE

Rosario

Congreso; Congreso Latinoamericano de Órganos Artificiales, Biomateriales e Ingeniería de Tejidos; 2014

Society of Biomaterials and Artificial Organs

Magnetic nanoparticles (MGNPs) are used for hyperthermia treatments for cancer, drug delivery, diagnostic-magnetic resonance imagining, etc. The chemical and physical characteristics of the MNPs play a critical role in determining successful interactions in each of these applications. Factors such as size, surface area, and magnetic properties are very important, but proper MNPs surface chemistry is integral to enhance colloid stability and cell interactions. The tendency for nanoparticles in suspension to agglomerate complicates the processing of stable nanoparticles suspensions and nanocomposites with a high degree of particles dispersion. There are many surface modification agents that are able to improve the colloidal stability of nanoparticles through electrostatic, steric or electrosteric effects but the chemistry of some of dispersants makes them unsuitable for use in biomedical applications. Gum Arabic (GA) is a unique dispersant that has been the subject of renewed interest as dispersant for metal oxides and magnetite among others. GA consists of three fractions with distinct chemical structures of polysaccharides. GA has been probed for the coating and increase biocompatibility (in vitro and in vivo studies) of iron oxide magnetic nanoparticles. The polymeric matrix from their functional groups, enhance the possibilities of interaction the magnetic composites with various substrates, including drugs. One of the goals of this study is to modify the MNPs with GA without using any crosslinking agent. This is for the purpose of developing a simple, easy and novelty method of synthesis GA onto MNPs. Furthermore, the focus of this study is to investigate and report how surface modification of MNPs with GA influences particle size (especially in water dispersions) and analyze studies of potential drug delivery e.g. a no steroidal anti-inflammatory such as diclofenac sodium and hyperthermia treatment. Two methods of synthesis of GA coated MNPs were evaluated employing the biopolymer in solid state and a solution of GA. The synthesis was performed by co-precipitating the iron oxide onto the GA. The magnetic materials obtained were characterized employing different techniques. FTIR analysis showed the presence of characteristics bands of GA and Fe3O4 confirming the incorporation of biopolymer in the MNPs. The hydrodynamic average size reveals values in the range of 50-80 nm for GA-MNP composites. These values were consistent with the TEM images obtained for the composites in water dispersion. Magnetic measurements resulted in values of 40.9 and 42.2 emu/g saturation magnetization for GA-Mag-a and b, respectively. From these assays it was possible the estimation of the size of the magnetic core, being 11 nm and 9.3 nm (considering spherical particles) for GA-Mag-a and b, respectively. These values and those obtained for DLS characterization suggest that the magnetic particles were effectively coated by GA. Moreover, it was quantified by ICP the Fe content and then it was calculated the magnetite content in each composite. The values of Fe3O4 content were 43.3 %w for GA-Mag-a and 53.8 %w for GA-Mag-b; these results were consistent with those estimated by magnetic measurements. Taking into account stability and average size obtained for GA-Mag composites, it is plausible their use as potential magnetically drug directed systems. A model drug for incorporation is Diclofenac, a widely used non-steroidal anti-inflammatory drug for the treatment of inflammatory disorders.