Development of carbonyl iron/ethylcellulose core/shell nanoparticles for biomedical applications

Protein-loaded PLGA microparticles engineered by flow focusing: Physicochemical characterization and protein detection by reversed-phase HPLC

“…The increasingly negative values and charge density may be explainable by the effect of increasing OH − ion concentration in the solution, which tends to favour a gain in protons. In contrast, a decrease in absolute as pH becomes more acidic may be explainable by neutralization of the negative regions as a result of chemical adsorption of increasing numbers of H + ions (Ruiz et al, 2004;Arias et al, 2007).…”

Development of iron/ethylcellulose (core/shell) nanoparticles loaded with diclofenac sodium for arthritis treatment

“…EC NPs were prepared following an emulsion solvent evaporation method (Arias et al, 2007). Briefly, EC (0.2 g) was dissolved in a mixture of organic solvents (0.2 g ethanol and 1 g benzene).…”

“…This formulation was then subjected to a cleaning procedure that included repeated cycles of centrifugation (30 min at 20,000 rpm, Centrikon T-124 high-speed centrifuge, Kontron, France) and re-dispersion in water, until the conductivity of the supernatant was ≤10 S/cm. Fe NPs were selected from 0.3% (w/v) Fe aqueous suspensions (BASF, Germany) by gravitational separation (Arias et al, 2006(Arias et al, , 2007. Briefly, during 10 min the suspensions were sonicated in 1 L flasks (internal diameter of ≈90 mm) and settling under gravity was carried out during 60 min, before taking the upper 10 mm of supernatant.…”

“…Finally, the method followed to obtain the magnetic nanocomposites was similar to that above described for the preparation of EC NPs, except that the aqueous phase contained the Fe nuclei [3.75%, w/v] (Arias et al, 2007). Cleaning of the core/shell NPs was achieved by repeated magnetic separation and re-dispersion in an aqueous medium containing pluronic ® F-68 (1%, w/v), until the conductivity of the supernatant indicated that the suspensions were sufficiently clean (≤10 S/cm).…”

“…This is a hydrophobic polymer, widely used in pharmaceutical technology, chemically stable under storage, and characterized by a great tolerability and lack of toxicity for patients (Dubernet et al, 1990;Kato et al, 1996;Zinutti et al, 1996;Grattard et al, 2002;DeMerlis et al, 2005). Iron (Fe) was chosen as a magnetic nucleus because of its high initial magnetic susceptibility and magnetic saturation (Arias et al, 2007), very low toxicity (LD 50 : 50 g/kg) (Chua-anusorn et al, 1999;Whittaker et al, 2002) and biodegradability [most Fe NPs of ≈350 nm prepared in this investigation will be eliminated mainly by renal filtration] (Okon et al, 1994). Even more, the inclusion of magnetic systems into polymeric materials does not increase the toxicity of the latter, as have been reported in clinical phase I trials (Ibrahim et al, 1983;Lübbe et al, 1996a,b).…”