Maleimide end-functionalized poly(2-oxazoline)s by the functional initiator route: synthesis and (bio)conjugation

Abstract

A new route for the synthesis of polyoxazolines with a maleimide end group is reported using a functional initiator.

Straightforward access to biocompatible poly(2-oxazoline)-coated nanomaterials by polymerization-induced self-assembly

“…5 Several studies have focused on the synthesis of functional PAOx to achieve functional hydrogels, [6][7][8] surface coatings, 9 and polymer-peptide/protein/drug conjugates. 10,11 Besides, the interest in PAOx-based complex structures is also increasing. 12 PEtOx brush-arm star and comb-shaped polymers incorporating nitroxide radicals and perfluorinated segments, respectively, have been reported for magnetic resonance imaging.…”

Thioacetate‐Based Initiators for the Synthesis of Thiol‐End‐Functionalized Poly(2‐oxazoline)s

“…Example of protecting groups incorporated in cROP initiators include N ‐alkylphthalimide or tert ‐butyl N ‐monoalkylcarbamate (for amines), [ 52–56 ] tert‐ butyldiphenylsilyl ethers (for hydroxyl), [ 57 ] methyl ester (for carboxylic acid or others through amidation), [ 58–63 ] and furanyl Diels–Alder cycloadduct (for maleimide). [ 64 ] Here, the thioacetate group has been chosen as a stable and economic protection group for thiols. [ 65 ] In the case of the tosylate initiator, ThioAcTos ( Scheme ), the synthetic route started with the nucleophilic substitution of allyl alcohol with tosyl chloride to yield allyl tosylate 1 (Scheme S1, Supporting Information).…”

“…The synthesis of PAOx proceeds through cationic ring‐opening polymerization (cROP), which allows full control of the polymer properties via tuning of the molar mass distributions and functionality, depending on the choice of the 2‐oxazoline monomer(s) and the specific end groups arising from initiation and termination. [ 19,24–27 ] Several strategies to graft PAOx on surfaces have been reported. [ 28,29 ] A simple and popular method uses α‐ or ω‐functional PAOx prepared with either a functional initiator or a terminating agent, to introduce (directly or after additional modification) a coupling moiety at one chain end.…”

A transient initiator for polypeptoids post-polymerization α-functionalization via activation of thioester group

“…We expect that reaction conditions critically influence the degree of conjugation and that further improvements are needed. BSA was selected as another model protein for conjugation due to its ready availability, robust nature, and the presence of an accessible free thiol at Cys-34 and 60 free amine groups available for conjugation [159][160][161]. The conjugation method uses a large excess of PSaroxid (Mw = 3.5 kg/mol).…”