Understanding the Polymer Rearrangement of pH-Responsive Nanoparticles

The use of self-assembled nanoparticles for drug delivery has received significant attention in recent years. However, the dynamic nature polymeric systems means there is a need to develop greater understanding inherent stability these systems. In particular, if materials remain as discrete nanoparticles, or exchange material between particles critical. Herein, we labelled pH-responsive with fluorescent dyes and then investigated change fluorescence when were mixed unlabelled order investigate their potential polymer rearrangement. Nanoparticles formed by nanoprecipitation poly(ethylene glycol)-block-poly(2-(diethylamino)ethyl methacrylate) (PEG-b-PDEAEMA) shell poly(2-(diethylamino)ethyl methacrylate)-random-poly(2-(diisopropylamino)ethyl (PDEAEMA-r-PDPAEMA) core. core incorporating pentafluorophenyl methacrylate (PFPMA) respectively coupling either Sulfo-cyanine5 amine Cyanine3 amine. Exchange was probed tracking changes self-quenching fluorescently polymers nanoparticles. intensity stable at physiological pH (pH 7.4), suggesting limited migration this system. This study provides important insights into non-crosslinked under biologically relevant conditions.