Device for collecting intestinal fluid

A device for collecting a sample of intestinal fluid comprising:

• a polymeric inner material:
• having an at least partially compressed open cell structure, and
• having a volume Vi,
• an elastic polymeric casing impervious to digestive fluid, said casing comprising at least one opening,
• a gastro-resistant material suitable for dissolving in intestinal fluid at 37° C. being disposed on top of each of said at least one opening;
• and
• at least one mechanism for closing the at least one opening, an intake of intestinal fluid into the device causing swelling of the inner material which induces a closure of the mechanism for closing the at least one opening,
• wherein the polymeric inner material is suitable for swelling to a volume greater than or equal to 1.1×Vi by absorbing intestinal fluid,
• wherein the elastic polymeric casing defines an inner volume where the polymeric inner material is disposed, and the polymeric inner material is configured to, once swollen with the intestinal fluid sample, occupy at least 80% of the inner volume formed by the elastic polymeric casing,
• wherein the casing encases the inner material, said at least one opening allowing the intake of intestinal fluid into the inner material, such that swelling of the inner material causes elastic deformation of the casing, and
• wherein the mechanism for closing the at least one opening comprises
• a flap impervious to intestinal fluid, the flap being inserted between the casing and the inner material and disposed under the at least one opening,
• a first film or first particles disposed between the flap and the casing and comprising a first polymer carrying hydroxyl, carboxylic acid and/or carboxylate functions;
• and
• a second film or second particles disposed between the first film or the first particles and the flap and comprising a second polymer carrying hydroxyl, carboxylic acid and/or carboxylate functions;
• where the first film or the first particles comprising the first polymer, the second film or the second particles comprising the second polymer and the casing form together channels whereby intestinal fluid is suitable for circulating and attaining the inner material, on condition that:
• the first and second polymers are suitable for reacting together to form a polyester during the circulation of intestinal liquid in the channels, when
• (i) the first polymer carries hydroxyl functions, the second polymer carries carboxylic acid and/or carboxylate functions, or
• (ii) the first polymer carries carboxylic acid and/or carboxylate functions, the second polymer carries hydroxyl functions.