Construction of biodegradable and biocompatible AIE-active fluorescent polymeric nanoparticles by Ce(IV)/HNO3 redox polymerization in aqueous solution.

Aggregation-induced emission (AIE) active fluorescence polymeric nanoparticles (FPNs) have recently received increasing interests for biomedical applications such as cell imaging, drug delivery, disease diagnosis and treatment. Fabricated strategies of AIE-active FPNs with high efficiency, simplification and tenderness are still passionately pursued to promote the development of theranostic systems. In this work, we develop a facile method for the preparation of AIE-active FPNs by adopting Ce(IV)/HNO3 redox polymerization under near room temperature. Thus-prepared FPNs (named as PEG-PLC-1) possess unique AIE feature, great water dispersity, excellent biocompatibility and biodegradability because of the conjugation of ultra-bright AIE dye (PhE-alc) and biodegradable PEG-PCL linear copolymers. The 1H nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), UV-Visible and fluorescence spectrometers were used to confirm the successful fabrication of AIE-active FPNs. Cell viability and cellular uptake behavior of PEG-PLC-1 FPNs were further investigated for their potential biomedical applications. Results demonstrated that PEG-PLC-1 FPNs are high water dispersity, intensive luminescence and low cytotoxicity, making them very attractive for biomedical applications. More importantly, the method for the fabrication of AIE-active biodegradable FPNs can be occurred under rather facile conditions (e.g., low temperature, free of metal catalysts, common chain transfer agent and aqueous solution) and are specially used for fabrication of AIE-active polysaccharides with poor organic solubility.