A novel fluorescent amphiphilic glycopolymer based on a facile combination of isocyanate and glucosamine

Abstract

A novel fluorescent amphiphilic glycopolymer (PhE-IM-Glu) was prepared through radical polymerization between an aggregation-induced emission (AIE) monomer (PhE) and 2-isocyanatoethyl methacrylate (IM), and subsequent glycosylation with glucosamine (Glu). The resulting PhE-IM-Glu could self-assemble to form polymeric nanoparticles with high dispersibility in aqueous solution due to the amphiphilic features, with hydrophilic glucose groups covered at the surfaces while the hydrophobic AIE components aggregated into the cores. This obtained PhE-IM-Glu copolymer was fully characterized by a series of techniques including gel permeation chromatography, ¹H NMR spectroscopy, FT-IR spectroscopy, and X-ray photoelectron spectroscopy, which firmly proved their successful syntheses. The morphology and distribution of these polymeric nanoparticles were confirmed by transmission electron microscopy and dynamic light scattering, showing spherical nanoparticles with diameters ranging from 100 to 150 nm and 184 ± 41 nm, respectively. UV-Visible absorption spectra and fluorescence spectra were also investigated to determine their optical performances, which demonstrated both good water dispersibility and high yellow fluorescence quantum yield (up to 41%) of PhE-IM-Glu. Finally, biocompatibility evaluation and cell uptake behaviour of the PhE-IM-Glu nanoparticles were further investigated to explore their potential biomedical applications. The demonstrated excellent biocompatibility and intense fluorescence efficiency made them promising for cell imaging. More importantly, the strategy of a facile combination of isocyanate and glucosamine in this work will provide a new way to prepare more and more novel biocompatible AIE-based fluorescent amphiphilic glycopolymers and may expand the scope of their real biomedical applications.