Selective accumulation of ionic nanocrystal H2 storage system as an in situ H2/boric acid nanogenerator fights against ethanol-induced gastric ulcers

Ethanol is a potential causative factor of gastric ulcers, which are associated with gastric injury and the overproduction of reactive oxygen species. Molecular hydrogen (H2) is reportedly a benign antioxidant and boric acid is an effective medication in repairing deep wounds. In this work, a nanoparticle system that consists of potassium borohydride ionic nanocrystals (KBH4 NCs) with a high H2 storage capacity is developed for the treatment and prevention of ethanol-induced gastric ulcers in mice. H2-rich water (HRW) is used as a control. Since the evolution of gaseous H2 from the HRW is abrupt, most of the evolved H2 gas is lost to the surrounding environment before and during oral administration. By contrast, KBH4 NCs can be trapped at the defect sites of ulcerated regions, reacting with the gastric fluid to generate sustainably gaseous H2 and boric acid, mitigating oxidative stress and excessive inflammation in tissues and repairing the gastric injury. Additionally, the protection that is afforded by gastric mucosa against ethanol-induced damage is stronger in mice that have been pretreated with KBH4 NCs than in those that have been pretreated with HRW, indicating the protective effect of KBH4 NCs. Overall, the data suggest that the as-developed KBH4 NCs are a promising oral formulation for the effective management of gastric ulcers.