Table 3.
Mechanism of Actions, Advantages, and Potential Drawbacks of Different Nitric Oxide Delivery Systems
| Type of delivery system | Mechanism | Advantages | Disadvantages |
|---|---|---|---|
| NO cylindersa | NO is pressurized in cylinders with nitrogen | Reliable, can deliver broad range of NO concentrations | Cumbersome, expensive, require supply chain, and trained personnel, limited to hospitals |
| Electrical NO generationa | High-voltage electricity through two metallic electrodes that ionize air, generating NO, NO2, and ozone. Filter and scavengers remove toxic metallic products, NO2, and ozone | Portable | Risk of release of by-products from air ionization. Dependent on air flow (i.e., the higher the flow, the lower the amount of NO production) |
| Chemical NO generationa | Generation of NO2 from vaporization of dinitrogen tetroxide, then reduction of NO2 through ascorbic acid to obtain NO. | Portable | Requires supply chain |
| Solutions releasing NO | Solutions that release NO when activated by change in pH | Studies currently limited to topical administration to treat cutaneous infections and prevent/treat mild or moderate COVID-19 (NCT04337918, NCT04163978) | |
| Nanoparticles releasing NO | Release of NO from nanoparticles containing NO or precursors | Potential application: topical administration to treat cutaneous infections | |
a
Commercially available.
COVID-19, coronavirus disease 2019; NO2, nitrogen dioxide.