LIFT hydrogels form within the stomach after oral administration of (1) a 200-ml crosslinker solution comprising CaCl 2 and a dithiol-containing molecule, followed by (2) a 20–40-ml polymer solution comprising alginate and four-arm PEG–maleimide. These two solutions (3) mix within the stomach to form a tough double-network hydrogel (4) within the stomach.
