Functionalised Porous Organic Polymers for Bioactive Nitric Oxide Delivery

Direct delivery of nitric oxide (NO) gas to a wound can promote healing and antimicrobial action, thus having a dual effect to combat the problem of chronic wounds. However delivery of NO gas is problematic due to toxic nature and short half-life, therefore novel NO-donors have been developed as potential topical therapeutic agents for wound care. The effectiveness of therapeutic agents significantly relies on their capability to deliver the desired amount of NO to a target site effectively.
N-nitrosamine and N-diazeniumdiolate moieties are capable of releasing NO in response to external stimuli such as light irradiation and physiological conditions (moisture, pH 7.4, 37 °C), respectively. Secondary amine groups can be converted to N-nitrosamine or N-diazeniumdiolate NO-donor groups to make novel NO-releasing materials. It is hypothesised that porosity can be introduced in the organic framework which will influence the rate of NO release, thus introducing an element of control over release kinetics.
In this work, porous organic polymers with multiple secondary amine sites were synthesised and modified post-synthetically to incorporate N-diazeniumdiolate moieties by reacting with pure NO gas. The subsequent NO release was measured by the Griess method.