Chromatic Dendrimer/Polydiacetylene Nanoparticles

Polydiacetylenes (PDAs) constitute a unique class of chromatic conjugated polymers, and their optical properties have been employed in diverse biological and chemical diagnostic applications. We constructed composite nanoparticles (NPs) comprising PDA and a dendritic amphiphilic polymer. The dendrimer/PDA NPs exhibit structural and chromatic stability and constitute an excellent platform for sensing and analysis of biomolecular membrane interactions, both in model vesicle systems and in a live-cell environment. Interestingly, the dendritic polymer shielded the PDA matrix and modulated its interactions with external stimuli such as heat and amphiphilic biomolecules. Furthermore, the dendrimer-layer-mediated association of the composite NPs with lipid bilayers in giant vesicles and live mammalian cells, thereby facilitating microscopic analysis of lipid bilayer interactions in actual membrane environments. The dendrimer/PDA NPs may serve as a broad-based vehicle for analysis of membrane interactions in diverse model and natural environments.