Moisture-saturated zeolites – A new strategy for releasing nitric oxide

Abstract

To cure ulcers inside the stomach and/or intestines caused by bacterial infection, a new strategy for releasing NO in the digestive system is proposed and verified. Nitric oxide, pre-adsorbed onto zeolite, when added to hydrochloric acid with a low pH (similar to that of gastric juice), releases NO into the solution; the amount of NO_x released can be tuned by altering the structure and modifier species of the zeolite. Various factors, including pH value, the temperature of acid solution, the volume ratio of liquid to solid, and the release time, are investigated to provide help understand the NO_x release mechanism from the moisture-saturated zeolites. We find that nitrite is produced in acid solution, which has advantages for controlled NO release because it provides an active storage mechanism for NO, and this is proved by in situ FT-IR experiments. Finally, we were able to simultaneously achieve the release of a large amount of NO and the capturing of nitrosamine by alumina-modified zeolite samples in the gastric juice mimic, affording a potential functional material to reduce the risk of ulcers and cancers in the digestive system.