The invention relates to a composition, especially for use in medicine, comprising a component a) containing cyanoacrylate monomers and an aqueous component b), wherein the composition further comprises an acid and a salt which reacts with the acid to release a gas. The invention further relates to a reaction product obtainable from the composition in the form of a porous and specifically shape-stable foamed structure in particular. The invention further relates to a kit comprising spatially separate from each other an acid component a) and a salt component b) and also to an applicator having a first chamber containing an acid component a) and a second chamber containing a salt component b).