Nitric oxide releasing two-part creams containing S-nitrosoglutathione and zinc oxide for potential topical antimicrobial applications

Currently, most antimicrobial topical treatments utilize antibiotics to prevent or treat infection at a wound site. However, with the ongoing evolution of multi-drug resistant bacterial strains, there is a high demand for alternative antimicrobial treatments. Nitric oxide (NO) is an endogenous gas molecule with potent antimicrobial activity, which is effective against a wide variety of bacterial strains. In this study, the potential for creating NO releasing creams containing the naturally occurring NO carrier, S-nitrosoglutathione (GSNO), are characterized and evaluated. GSNO is shown to have prolonged stability (> 300 days) when mixed and stored within Vaseline at 24 degrees C. Further, enhanced proliferation of NO from GSNO using zinc oxide nanoparticles (ZnO) is demonstrated. Triggering NO release from the GSNO/Vaseline mixture using a commercial zinc oxide-containing cream exhibits first-order NO release kinetics with the highest %NO release over the first 6 h. Significant killing effects against S. aureus, S. epidermidis, and P. aeruginosa are demonstrated for the GSNO/Vaseline/ZnO cream mixtures in a proportional manner dependent upon the concentration of GSNO in the final mixture.