Perylene Bisimides-incorporated Water-soluble And Fluorescent Polyurethane For Living Cell Labeling

Water-solubility is always an essential factor when consider the potential of perylene bisimides(PBIs)for their biomeidical applications,although these analogs generally possess high quantum yields,high extinction coefficients,and high chemical and photophysical stability.In view of this situation,perylene bisimides-incorporated polyurethanes(HDI-PBI-PEG)were synthesized from poly(ethylene glycol)(PEG),PBIs,and hexamethylene diisocyanate(HDI)using the facile and well-established method for common polyurethane preparation.The chemical component and molecular weight of the HDI-PBI-PEG copolymers were characterized by 1H NMR,FTIR,and gel permeation chromatography(GPC),respectively.Copolymerization greatly improved the solubility of this rigid aromatic diimides,and hence the resulted copolymers were not only soluble in polar-organic solvent but also can be easily dissolved in water.The HDI-PBI-PEG have shown great potential for their application as a universal cell labeling agent,as convinced by their high fluorescence in aqueous solutions,lack of cytotoxicity towards mammalian cells,rapid internalization by cells,and intensive and stable light emission from the labeled cells.Furthermore,after the folic-acid conjugation,the FA-HDI-PBI-PEG exhibits significantly higher efficiency in labeling skov-3 cells than the normal mammalian cells.