Synthesis of biocompatible glycodendrimer based on fluorescent perylene bisimides and its bioimaging

A novel water-soluble fluorescent glycodendrimer based on perylene bisimides is synthesized, which exhibits high fluorescence quantum yield of 54%. While the binding interactions of PBI-Man with Concanavalin A (Con A) are studied by fluorescence spectra and CD spectra, which show strong binding affinity for Con A with the binding constant of 3.8 × 10(7) m(-1) for monomeric mannose, nearly four orders of magnitude higher affinity than the monovalent mannose ligand. Furthermore, the fluorescence imaging of macrophage cell with PBI-Man is investigated, and shows selectively binding interaction with the mannose receptor-medicated cell entry. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) activities of PBI-Man show that PBI-Man as a biocompatible agent is noncytotoxic to living cells.