Comprehensive evaluation of S-nitrosoglutathione and S-nitroso-N-acetylpenicillamine stability in biomedical contexts

Nitric oxide (NO) is a potent signaling molecule with great therapeutic potential. However, the clinical application of direct NO delivery is limited by its short half-life and high reactivity, which creates challenges for effective controlled delivery. To overcome these limitations, S-nitrosothiols (RSNOs) are commonly used as NO donors in therapeutic applications, as they stabilize the short-lived free radical and improve NO pharmacokinetics. Despite their widespread use, the stability and release kinetics of RSNOs under physiological conditions have not been thoroughly evaluated, which is crucial for determining their therapeutic efficacy and safety. This study provides a comprehensive evaluation of the stability and in vitro NO release profiles of two commonly used RSNOs, S-nitrosoglutathione (GSNO) and S-nitroso-N-acetylpenicillamine (SNAP), at physiologically relevant conditions. Using a range of analytical techniques, including electrospray ionization mass spectrometry, Griess assay, and electrochemical sensing, we assessed RSNO stability across various conditions, including different buffers, pH levels, temperatures, as well as exposure to UV light irradiation to simulate common sterilization practices. Additionally, we investigated RSNO stability in cell culture media with varying glucose levels and serum compositions to better mimic biological environments. Our findings provide critical insights into the factors affecting RSNO stability and NO release, advancing the development of more effective NO-based therapies and biomedical devices.