Synthesis of Thermoresponsive Glycopolymers Combining RAFT Polymerization, Thiol‐Ene Reaction, and Subsequent Immobilization onto Solid Supports

Abstract

A new monomer, N‐hexenylacrylamide, is copolymerized with N‐isopropylacrylamide by reversible addition‐fragmentation chain transfer (RAFT) polymerization using a carboxylic‐acid‐functionalized RAFT agent. Subsequently, the resulting functional copolymers are reacted with acetylated thiogalactose via a thiol‐ene reaction. After deprotection of the sugar acetyl groups, the glycopolymers show a lower critical solution temperature (LCST) behavior, as confirmed by turbidity measurements. One of these glycopolymers is subsequently immobilized onto solid supports. The obtained products are characterized by attenuated total reflection Fourier transform IR (ATR FTIR) spectroscopy, thermal gravimmetric analysis (TGA), and elemental analysis, confirming the immobilization of the glycopolymer. Additionally, the glycopolymer‐functionalized support shows interaction with the lectin RCA120.

Design of Thermoresponsive Elastin-Like Glycopolypeptides for Selective Lectin Binding and Sorting

“…In our work, the interaction between ELP­(Gal) and RCA 120 allows the formation of such structures, most likely because RCA 120 possesses two binding sites in its native form. As reported in the literature, the preparation of stimuli-responsive glycopolymers that are able to simultaneously enhance and control the lectin–glycopolymer interaction is challenging, but has also been achieved by several research groups. − Heise et al reported the synthesis of a glycopolypeptide via ring-opening polymerization and click chemistry with combined lectin recognition and thermoresponsive properties . Additionally, similar aggregation behavior to the one evidenced in this work was also observed for thermoresponsive polymers with pendant glucose functionality, which formed aggregates with bacterial cells and were assembled/disassembled reversibly through temperature cycling …”

Tailor-made glycopolymersviareversible deactivation radical polymerization: design, properties and applications

“…In addition to the azide–alkyne “click chemistry”, the use of thiol–ene “click chemistry” is very popular for the introduction of sugar moieties in the polymer chain via post-modification. 30,44,133,134 The thiol–ene reactions are extremely fast and have high tolerance against a wide range of reaction conditions and functional groups. 135 Importantly, under biological conditions, the thioglycosidic linkage of the sugar units are more stable against enzymatic degradation as compared to the O -glycosidic linkages.…”

“…After deacetylation, the resulting glycopolymer was immobilized on solid surfaces and its interaction with lectin RCA 120 was studied. 133…”