Redox- and glucose-induced shape-memory polymers

Abstract

A novel redox-induced shape-memory polymer (SMP) is prepared by crosslinking β-cyclodextrin modified chitosan (β-CD-CS) and ferrocene modified branched ethylene imine polymer (Fc-PEI). The resulting β-CD-CS/Fc-PEI contains two crosslinks: reversible redox-sensitive β-CD-Fc inclusion complexes serving as reversible phases, and covalent crosslinks serving as fixing phases. It is shown that this material can be processed into temporary shapes as needed in the reduced state and recovers its initial shape after oxidation. The recovery ratio and the fixity ratio are both above 70%. Furthermore, after entrapping glucose oxidase (GOD) in the system, the material shows a shape memory effect in response to glucose. The recovery ratio and the fixity ratio are also above 70%. A redox-induced shape-memory polymer is prepared by crosslinking β-cyclodextrin modified chitosan and ferrocene modified branched poly(ethylene imine). The reversible redox-sensitive β-CD/Fc inclusion complexes and covalent crosslinks serve as reversible phases and fixing phases, respectively. The shape memory behavior also happens when glucose is introduced with glucose oxidase entrapped in the system. The recovery ratio and fixity ratio are above 70%. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.