Nanostructured biocompatible systems for target drug delivery

In this research, we have developed surfactant-assisted methods to produce polymeric, ceramic and composite nanoparticles. We have shown that, depending on water/oil/surfactant composition and the homogenization system, the particle size is greatly affected. Polymeric particles prepared by cross-linking of the albumin (BSA) or polyallylamine (PALA) with glutaraldehyde have considerable interest for their use as a delivery vehicle for various pharmaceutical agents and as models to develop innovative nanocomposites. MnFe2O4 magnetic nanoparticles have been synthesized by using reverse-micelles as nanoreactors. The coprecipitation of Mn2+ and Fe3+ ions in alkaline solution produced a hydroxide precursor which is been transformed in manganese ferrite by calcination. The superparamagnetic behaviour of sample calcined at 600°C certainly demonstrated that obtained MnFe2O4 is a nanocrystalline system and that each crystallite exists as a single magnetic domain. The magnetic nanoparticles were entrapped in albumin cross-linked with glutaraldehyde. The composite nanoparticles consist of superparamagnetic nanoparticles distributed in a polymeric network that provides functional groups for further derivatization. In order to demonstrate drug loading and release efficacy of the developed carriers, a model drug was entrapped or adsorbed on the materials. Results from antibiotic entrapment evidenced that the antibiotic delivery is restricted by the limited ability of the drug to diffuse out of particle. Adsorbed drug is resulted active against Gram-positive bacteria (S. epidermidis) for ~8 days when adsorbed on the polymeric nanoparticles and for ~ 2 days in the composite nanoparticles case. The interaction of produced materials with cells was studied using an in vitro assay. The materials did not affect the cell morphology. Nevertheless, the materials can not easily characterized in vitro for their expected in vivo behaviour since it must be said that the in vitro characterization of biomaterials is not sufficient to predict their real in vivo behaviour and their biocompatibility. It is well known that several physico-chemical and biological factors can affect their interactions with the body elements, and that they must be evaluated under specific physiological and pathologic conditions.