Synthesis of thermoresponsive glycopolymers via ATRP of N-isopropylacrylamide and N-allylacrylamide and subsequent thiol–ene reaction

To prepare thermoresponsive glycopolymers, new alkene functional copolymers based on N-isopropylacrylamide were synthesized and functionalized with sugar moieties. The copolymerization of N-isopropylacrylamide with N-allylacrylamide by ATRP led to soluble, well-defined polymers which were reacted with 1-thiosugars via a thiol–ene reaction. In addition to 1H NMR spectroscopy, FT-IR spectroscopy, elemental analysis and size exclusion chromatography, the glycopolymers were characterized by turbidimetry, which revealed sharp and reversible coil-to-globule transitions of the prepared copolymers. Furthermore, lectin binding studies revealed the interaction of the galactosylated polymers to the lectin RCA120 depending on their degree of functionalization. The results demonstrate that the discussed synthetic strategy represents a practical and flexible route towards functional N-isopropylacrylamide copolymers.