A Janus adhesive sealant with extreme acid-tolerance for gastric perforation repair.

Although Janus adhesive sealants hold great potential for gastric perforation repair, current versions fail to achieve stable and durable sealing in highly acidic gastric fluid. Herein, we employ the homogeneous hydrophobic strategy for the first time to develop a Janus adhesive patch with extreme acid-tolerance for gastric perforation repair. The patch is fabricated by unilaterally immersing a Cu2+-crosslinked lipoic acid (LA) gel into a chitosan oligosaccharide (COS) solution (Cu@LA-COS). Owing to the homogeneously hydrophobic poly(LA) network that can durably repel both water molecules and hydronium ions, the Cu@LA-COS patch maintains a stable adhesive strength exceeding 42 kPa even after 14 days of immersion in highly acidic simulated gastric fluid. In addition, the Cu@LA-COS patch exhibits anti-inflammatory and pro-angiogenic activities, achieving complete gastric wound closure in Sprague-Dawley rats with gastric perforation within 14 days, with a regenerated mucosal layer thickness comparable to that of healthy stomach. This extremely acid-tolerant Janus adhesive Cu@LA-COS patch, capable of durably sealing gastric defects and preventing postoperative adhesion, is a promising sealant for gastric perforation repair.