Dual-network hydrogel based on ionic nano-reservoir for gastric perforation sealing

Abstract

In recent years, remarkable progress has been made in the research of injectable hydrogel for internal tissue healing. However, the therapeutic outcome is usually limited when the hydrogel is used for the treatment of gastric perforation due to the high acidic gastric juice and violent deformation of the gastric wall. Regarding these challenges, we proposed an ionic nano-reservoir (INR)-based dual-network hydrogel, which has excellent adhesion and mechanical properties, and can be easily applied to the perforation site to block the perforation while promoting tissue repairing. The results showed that the first network made of polyacrylamide had cross-linked on the stomach tissue within 5 s under blue light, and enhanced the adhesion performance through mechanical interlock. The nano-hydroxyapatite acted as ionic INR, which can gradually release Ca2+ under acid environments to form the second network with sodium alginate and inhibit the swelling of hydrogel in gastric juice. Meanwhile, the adhesion was further enhanced through amide covalent bonds at the hydrogel-tissue interface with the presence of 1- ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS). The dual network hydrogels obtained by the INR strategy could be employed as a potential therapeutic option for gastric perforation and other similar biomedical prolems.