Synthesis of fluorescent ABA triblock copolymer via click reaction

A hyperbranched-linear-hyperbranched (ABA) triblock copolymer containing poly(ethylene glycol) (PEG) as linear block and polyglycerol (hbPG) as hyperbranched blocks has been synthesized through a copper-catalysed click reaction. In order to synthesize the hyperbranched block, propargyl alcohol-initiated ring-opening multibranching polymerization of glycidol was used to prepare hbPG with the propargyl segment in the focal point (CHChbPG). Separately, PEG was functionalized at both ends using cyanuric chloride, and then the chloride groups of cyanuric chloride were substituted by azide groups. Finally, the azide-functionalized PEG was conjugated to CHChbPG via a click reaction. Substitution of the chlorine atoms of cyanuric chloride under different conditions together with click chemistry allows the synthesis of a variety of polymeric architectures. In the last step, fluorescein was attached to the block copolymer as a fluorescent probe in order to study the cell internalization of this copolymer. This type of triblock copolymer is a promising future nanomaterial for simultaneous drug delivery and cell imaging. (c) 2016 Society of Chemical Industry