Development of a Sustained-release System for Nitric Oxide Delivery using Alginate/Chitosan Nanoparticles

Free radical nitric oxide (NO) has been known to interact with various physiological processes, such as wound repair processes and control of vascular tone. However, NO is an unstable molecule and the development of NO delivery systems that enhance its stability has also been studied. In this work, alginate/chitosan nanoparticles have been studied as a drug delivery system of the S-nitrosoglutathione (GSNO) as NO donor. For this, glutathione, GSH, the GSNO precursor, was encapsulated in alginate/chitosan nanoparticles. The presence of GSNO was confirmed by UV spectra at 336 nm. Alginate/chitosan nanoparticles with negative and positive surface charges were obtained by increasing the chitosan amount. The encapsulation efficiency (EE) relied on the nanoparticle zeta potential, obtaining 80% of EE for positive particles. The NO release from GSNO showed that polymeric nanoparticles lead to the stabilization of GSNO decomposition, at physiological temperature. Moreover, this system did not exhibit cytotoxicity for fibroblast V79 cells up to the maximum concentration tested (18 mu molL(-1)). These results showed that alginate/chitosan nanoparticles are interesting particles to encapsulate NO donors for biomedical applications where NO might have a therapeutic effect.