Nitric oxide (NO) and silver nanoparticles (AgNPs) are well-known for their antibacterial activity. In this work, S-nitroso-mercaptosuccinic acid (S-nitroso-MSA), a NO donor, and green tea synthesized AgNPs were individually or simultaneously incorporated into alginate hydrogel for topical antibacterial applications. The obtained hydrogels were characterized and the NO release and diffusion of AgNPs and S-nitroso-MSA from alginate hydrogels were investigated. The hydrogels showed a concentration dependent toxicity toward Vero cells. The potent antibacterial effect of the hydrogels was demonstrated toward Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, and Streptococcus mutans UA159. Interestingly, the combination of S-nitroso-MSA and AgNPs into alginate hydrogels had a superior antibacterial effect, compared with hydrogels containing S-nitroso-MSA or AgNPs individually. This is the first report to describe the synthesis, cytotoxicity, and antibacterial effects of alginate hydrogel containing NO donor and AgNPs. These hydrogels might find important local applications in the combat of bacterial infections.
Keywords: S-nitrosothiol; alginate hydrogel; cytotoxicity; multiresistant bacteria; nitric oxide; silver nanoparticles.