Schematic representation of the mechanism of NO release from an RSNO such as SNAP. The mechanism involves the oxidation of Cu⁰ nanoparticles to Cu²⁺ ions in the presence of water. NO, nitric oxide; SNAP, S-nitroso-N-acetylpenicillamine; Cu, copper; NP, nanoparticle; RSNO, nitrosothiol NO donor; RS⁻, thiolates. (Adopted from Pant J, Goudie MJ, Hopkins SP, Brisbois EJ, Handa H. Tunable Nitric Oxide Release from S-Nitroso-N-acetylpenicillamine via Catalytic Copper Nanoparticles for Biomedical Applications. ACS Appl Mater Interfaces. 2017;9(18):15254–15264 [125]. Copyright © 2017, American Chemical Society. With permission from Applied Materials.)