Polymer microcapsules with carbohydrate-sensitive properties

Carbohydrate-sensitive polymer multilayers are assembled onto flat substrates and colloidal CaCO3 particles via reversible covalent ester formation between the polysaccharide mannan and phenylboronic acid moieties grafted onto poly(acrylic acid) (PAA). The resulting multilayer films are sensitive to several carbohydrates, and show the highest sensitivity to fructose. The response to carbohydrates arises from the competitive binding of small molecular weight sugars and mannan to boronic acid groups within the films, and is observed as a rapid dissolution of the multilayers upon contact with a sugar-containing solution above a critical concentration. In addition, carbohydrate-sensitive multilayer capsules are prepared, and their sugar-dependent stability is investigated by following the release of encapsulated tetramethylrhodamine isothiocyanate-bovine serum albumin (TRITC-BSA).