Synthesis of glucose-sensitive self-assembled films and their application in controlled drug delivery

Hydrogen-bonded layer-by-layer assembled films from poly(vinyl pyrrolidone) and poly(acrylic acid) were crosslinked with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and ethylene-diamine, and modified with 3-aminophenylboronic acid and isopropylamine simultaneously. The resultant films present pH- and thermosensitive swelling behaviors. Furthermore, the swelling of the films is enhanced when saccharides, such as glucose or fructose, is present in the solution. Alizarin Red S (ARS) was used as a model drug to study the drug release behavior of the films. The loading amount of ARS increases with increasing ARS concentration, which binds covalently with the phenylboronic acid groups in the film. The release of ARS is faster in the presence of glucose, which competes with ARS for binding sites in the film. The novel multistimuli-sensitive films may find applications in self-regulated insulin delivery. (C) 2009 Elsevier Ltd. All rights reserved.