Thermoresponsive block copolymers containing reactive azlactone groups and their bioconjugation with lysozyme

Hien The Ho, Martin E. Levere, Sagrario Pascual, Véronique Montembault, Nathalie Casse, Aurore Caruso, Laurent Fontaine

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40 Citations (SciVal)


Thermoresponsive block copolymers based on poly(ethylene oxide) (PEO) and poly(N-isopropyl acrylamide) (PNIPAM) containing azlactone groups along the backbone and at the chain-end of the macromolecular chain were synthesized by statistically reversible addition-fragmentation chain transfer (RAFT) copolymerization and by using a combination of RAFT polymerization and thiol-ene Michael addition. Well-defined poly(ethylene oxide)-b-poly(2-vinyl-4,4- dimethylazlactone-co-N-isopropyl acrylamide) (PEO-b-P(VDM-co-NIPAM)) block copolymers and azlactone-terminated poly(ethylene oxide)-b-poly(N-isopropyl acrylamide) (PEO-b-PNIPAM-VDM) diblock copolymers with low polydispersity indices (PDIs ≤ 1.10) were prepared and fully characterized by 1H NMR spectroscopy, FT-IR spectroscopy, and SEC. Such PEO-b-P(VDM-co-NIPAM) block copolymers and azlactone-terminated PEO-b-PNIPAM block copolymers present tunable lower critical solution temperature (LCST) depending on PEO, PNIPAM, and PVDM molar ratios. The reactivity of the PEO44-b-P(VDM 20-co-NIPAM80) copolymer (Mn,NMR = 14200 g mol-1, PDI = 1.08) and of the PEO44-b-PNIPAM 101-VDM copolymer (Mn,NMR = 13700 g mol-1, PDI = 1.08) was studied with lysozyme as a model protein. A bioconjugate with a higher apparent molecular weight was obtained with the PEO44-b- P(VDM20-co-NIPAM80) copolymer in comparison with the one obtained using the PEO44-b-PNIPAM101-VDM copolymer as shown by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The results suggest promising applications of azlactone-functionalized polymers within the field of bioconjugation.

Original languageEnglish
Pages (from-to)675-685
Number of pages11
JournalPolymer Chemistry
Issue number3
Publication statusPublished - 7 Feb 2013

ASJC Scopus subject areas

  • Bioengineering
  • Biochemistry
  • Polymers and Plastics
  • Organic Chemistry


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