S-nitrosoglutathione-containing chitosan nanoparticles dispersed in Pluronic F-127 hydrogel: Potential uses in topical applications

The aim of this study was to prepare nitric oxide (NO) releasing nanoparticle/hydrogel with potential uses in topical applications. NO is a signaling molecule in skin. It controls the dermal blood flow, skin defense, and tissue repair. There is an interest for designing topical formulations that release NO/NO donors directly at the desired application site. S-nitrosoglutathione (GSNO), a NO donor, was incorporated into chitosan nanoparticles (CS NPs) (hydrodynamic size of 112.2 +/- 2.22 nm). Free GSNO or GSNO-containing CS NPs were incorporated in Pluronic F-127 (PL) hydrogels. The purpose of this study was to combine the advantages of CS NPs (as a drug delivery system with mucoadhesive properties) and a PL hydrogel, which permits a prolonged contact time for the NO donor on the mucosal/skin surfaces. Rheological measurements were performed to determine the sol-gel transition temperature, the rheological parameters, and the viscosity. The polymeric matrices spontaneously released free NO. GSNO diffusion from the polymeric matrices was evaluated using a diffusion system. The results indicate that the incorporation of GSNO-CS NPs into a PL hydrogel may find important dermatological applications due to their mechanical properties and their ability to release therapeutic and sustained amounts of NO at the desired application site. (AU)