Fabrication of water dispersible and biocompatible AIE-active fluorescent polymeric nanoparticles through a “one-pot” Mannich reaction

Fluorescent nanoparticles have been attracting more and more interest from scientists in chemistry, materials, medical and biology fields. Among them, fluorescent nanoparticles with aggregation-induced emission (AIE) character stand out as the most promising candidates for different applications especially in the biomedical field. In this work, we reported for the first time that amphiphilic polymers containing a hydrophobic AIE dye and a hydrophilic poly(ethylene glycol) (PEG) segment can be facilely fabricated based on a Mannich reaction, which could conjugate the phenol hydroxyl-containing AIE dye (PhE-OH), paraformaldehyde and 4-arm poly(ethylene glycol)amine (4-arm PEG-NH2) in one pot. The obtained PEG-PhE fluorescent polymeric nanoparticles (FPNs) were ascertained by a series of characterization techniques. Moreover, the cell viability and cell uptake behavior of PEG-PhE FPNs were also investigated to evaluate their potential for biomedical applications. The results suggest that the PEG-PhE FPNs show great potential application in the field of biomedical science. More importantly, the strategy used in this work can also be extended for the preparation of many other various AIE-active FPNs with different functional polymers.