Structural Design of Polymers Conjugated with Bifunctional Chelating Agents

Recently, there has been a growing interest in conjugates of polymers with bifunctional chelating agents (BFCAs). BFCAs containing multiple amino and carboxyl groups, in the literature referred to as chelating agents of polyamino polycarboxylic (PAPC) structure, are particularly interesting due to their ability to form highly stable complexes with a wide variety of metal ions. This review covers the synthesis of macromolecules conjugated with BFCAs of PAPC structure. First, the PAPC chelating agents are briefly described and possible ways of activation of their one or more functional groups to react with polymers is discussed. Next chapters focus on polymer-PAPC conjugates and routes for their synthesis, either by the reactions of ligand with a monomer and further polymerization (route A), or by the post-polymerization modification of polymers with BFCAs (route B). We emphasize whether the PAPC chelating compounds are located at the polymer chain end(s), or in the substituents, what is important for further applications. Also, we pay a special attention to the conjugation reaction conditions. The use of polymer-PAPC conjugates in biology and medicine is gently highlighted. Advances especially over the past decade are gathered in this work.