Characterization of novel nitrite-based nitric oxide generating delivery systems for topical dermal application

Area of Science:

• Biomedical Engineering
• Dermatology
• Materials Science

Background:

• Topical nitric oxide (NO) shows therapeutic potential for chronic wounds, impaired microcirculation, and skin infections.
• Traditional nitrite-based NO-donor systems cause skin inflammation and toxicity due to uncontrolled NO release and low pH.
• Existing systems require modification for safer and more effective dermal application.

Purpose of the Study:

• To develop a modified nitrite-based NO-donor system for topical dermal application with reduced side effects.
• To investigate the impact of pH, ascorbic acid, and copper ions on NO generation kinetics and yield.
• To assess the influence of NO release kinetics and dose on fibroblast toxicity.

Main Methods:

• Developed a modified nitrite-based NO-donor system using a pH-stable acetate/acetic acid buffer (pH 5.5) and sodium ascorbate.
• Investigated the effect of copper (Cu(2+)) ions on NO generation.
• Utilized a fibroblast cell culture assay with gas-permeable membranes to study NO release and penetration kinetics and their effect on cell toxicity.

Main Results:

• The modified system achieves sustained NO generation without excessive peaks, unlike previous methods.
• Copper ions significantly enhance NO generation through a Cu(2+)/ascorbate redox mechanism.
• NO release kinetics, particularly concentrations in the initial 200s, significantly influence cell toxicity, independent of the total NO dose.

Conclusions:

• A novel, skin-compatible nitrite-based NO-donor system has been developed for topical dermal application.
• The system provides well-defined NO concentrations at a skin-neutral pH, minimizing adverse effects.
• This improved NO delivery system holds promise for treating chronic wounds and impaired microcirculation with enhanced safety and efficacy.