Gliadin nanoparticles: formation, all-trans-retinoic acid entrapment and release, size optimization

Abstract

Gliadin nanoparticles were prepared by a desolvatation method. They showed good stability during several weeks in PBS or aqueous medium. Assayed as carriers for all-trans-retinoic acid (RA), they have a quite good entrapment efficiency: about 75% of added drug at 60 μg• (mg gliadin) −1 and a payload of 76.4 μg• (mg gliadin)−1 nanoparticles. A rapid release of 20% of the drug after 15 min in sink conditions and a diffusion process in a second step are observed. According to the nature of vegetal proteins, the size control of the nanoparticles may be reached by varying the nature of the solvent, the pH and the ionic strength. Because gliadin is poorly solubilized in aqueous solutions, the first method was chosen. In order to quantify more precisely the solvent effect, the size diameter was optimized through a solubility parameter study. The smallest size was reached for protein solubility solvent equal to that of gliadin. Size differences were observed with respect to the process steps; the diameter obtained after nanoprecipitation fluctuates with time. © 1999 Society of Chemical Industry