Light Triggered Nitric Oxide Release from N-Nitroso Porous Organic Polymers

Nitric oxide (NO) deficiency caused by ageing or disease such as diabetes can result in chronic, non-healing wounds and an increased risk of infection. Direct delivery of NO to a wound site can promote healing and antimicrobial action. As a potential topical therapeutic agent, its effectiveness significantly relies on NO gas delivery methods capable of delivering the desired amount of NO to the targets effectively. N-nitrosamine and N-diazeniumdiolate NO-donor groups have received much attention recently, as they can release NO in response to external stimuli such as light irradiation, pH and temperature. Control over NO release by incorporating NO-donor groups into carrier materials such as polymers or silica nanoparticles has been employed in an attempt to achieve targeted delivery and extended release duration. We have developed porous organic polymers with dihydropyridine moieties and BET surface areas ranging 67- 430 m2g-1. Solid state 13C NMR and FTIR were employed to characterise polymer structures, and the conversion of >NH to >N-NO was identified by characteristic IR bands at ~ 1500 cm-1 and 970 cm-1. The N-nitroso moiety is light sensitive and exposure to light irradiation (365 nm) releases NO in aqueous solution. The Griess method was used for the determination of NO released over time.5