Thermo-Responsive Glycopolymer Chains Grafted onto Honeycomb Structured Porous Films via RAFT Polymerization as a Thermo-Dependent Switcher for Lectin Concanavalin A Conjugation

Stable and surface-modified films with regular porous arrays were created by crosslinking honeycomb structured porous films prepared via breath figures from poly(styrene-co-maleic anhydride). The formation of open or closed pores of the films was controlled by the addition of a polyion complex. Subsequent crosslinking of the films with 1,8-diaminooctane led to films, which maintain their structure in solvents. In addition, excess amino functionality after crosslinking allowed the attachment of RAFT agent, 3-benzylsulfanyl thiocarbonyl sulfanylpropionic acid, for the controlled surface polymerization of N-isopropyl acrylamide (NIPAAm) and N-acryloyl glucosamine (AGA). The attachment of thermo-responsive glycopolymers onto the honeycomb structured porous films was confirmed using contact angle measurements and confocal fluorescence microscopy. Cleavage of surface anchored polymers via aminolysis revealed that the molecular weights of the surface grafted chains are significantly larger than the molecular weight of the chains generated in solution. The honeycomb structured porous films with their grafted PNI-PAAm-ran-PAGA polymer chains showed selective recognition of Concanavalin A (ConA). Below the lower critical solution temperature (LCST) of the surface, the conjugation is switched off, while above the LCST the surface grafted glucose moieties bind strongly to ConA. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3440-3455, 2010