Easy functionalization of amphiphilic poly(ethylene oxide)-b-poly(ε-caprolactone) copolymer micelles with unprotected sugar: synthesis and recognition by lectins

Abstract

This paper aims at reporting the end-functionalization of a PEO block of an amphiphilic α-acetal-PEO-b-PCL copolymer. The acetal end-group, which is the fragment of the initiator used in the EO polymerization, was first hydrolyzed into an aldehyde that was then reacted with an amine by reductive amination reaction in water. This two-step derivatization was carried out in one pot. In a preliminary study a model amine, i.e. fluorescein amine, was used and the impact of the composition, thus of the Hydrophilic–Lipophilic Balance (HLB) of the amphiphilic copolymer, was studied. The experimental conditions were extended to the coupling of an aminated mannose to the diblock copolymer. The frozen micelles formed by the mannosylated copolymer proved to form complexes with various lectins as shown by Surface Plasmon Resonance (SPR) and Isothermal Titration Calorimetry (ITC).