Core-independent approach for polymer brush-functionalised nanomaterials with a fluorescent tag for RNA delivery.

Here we describe a core-independent approach enabling the grafting of polymer brushes from the surface of nanomaterials and microparticles for oligonucleotide delivery. This method is based on the adsorption of a polyelectrolyte macroinitiator (MI) combined with a fluorescent conjugated polymer for efficient and stable labelling. This allows dense brushes to be generated, with growth kinetics comparable to those observed from mono-functional initiators, for the imaging of nanomaterial cellular localisation and uptake. We also study the impact of brush chemistry on interactions with cell membranes and on transfection efficiency. The method we report offers a unique freedom of design of the core size and shape as well as surface chemistry, whilst enabling tagging, for the study of transfection processes or theragnostic applications.