Synthesis and cell-induced luminescence of post-functionalisable ionisable polyesters from the Passerini 3-component polymerisation

Recent developments in polymer synthesis methods allow the preparation of new materials across a wide chemical space and with high atom efficiency. In this work, we developed a strategic approach to the synthesis of a diverse array of novel ionisable polyesters via a modular and iterative synthetic approach. We initially designed a range of diacid monomers and subsequently used the Passerini 3-component reaction as a simple, one-pot step growth polymerisation to build a library of novel, highly functionalised polymers. This library was expanded further by the application of thiol/ene and copper-initiated azide/alkyne click chemistries to introduce further structural diversity into the materials. Selected polymers were found to internalise readily in a model cell line (HEK-293T), and for a subset of these polymers, bright luminescence was observed in the cells upon internalisation, even though neither the cells, nor the polymers, were luminescent on their own at these wavelengths. Our synthetic approach offers a versatile platform for the systematic development and modification of novel macromolecules and for cell-labelling components.