Synthesis, Characterization, and Biological Assays of Chitosan Nanoparticles and Alginate Hydrogels Containing Nitric Oxide Donor for Topical Applications

This work describes the development and characterization of a nitric oxide (NO)–releasing biomaterial based on chitosan nanoparticles embedded in alginate hydrogels for topical biomedical applications. S-nitrosothiol NO donors were incorporated into chitosan nanoparticles to enable controlled and sustained NO release, overcoming the intrinsic instability of free NO in biological environments. The system was characterized using physicochemical techniques and evaluated through in vitro diffusion and biological assays, demonstrating diffusion-controlled NO release and favorable biological response. These findings highlight the potential of this platform for topical therapeutic applications, including antimicrobial, wound-healing, and cancer-related treatments.