Synthesis and biological characterization of a new fluorescent probe for vesicular trafficking based on polyazamacrocycle derivative

The fluorescent probes represent an important tool in the biological study, in fact characterization of cellular structures and organelles are an important tool-target for understanding the mechanisms regulating most biological processes. Recently, a series of polyamino-macrocycles based on 1,4,7,10-tetraazacyclododecane was synthesized, bearing one or two NBD units (AJ2NBD·4HCl) useful as sensors for metal cations and halides able to target and to detect apolar environment, as lipid membranes. In this paper, we firstly illustrate the chemical synthesis of the AJ2NBD probe, its electronic absorption spectra and its behavior regarding pH of the environment. Lack of any cellular toxicity and an efficient labelling on fresh, living cells was demonstrated, allowing the use of AJ2NBD in biological studies. In particular, this green fluorescent probe may represent a potential dye for the compartments involved in the endosomal/autophagic pathway. This research's field should benefit from the use of AJ2NBD as a vesicular tracer, however, to ensure the precise nature of vesicles/vacuoles traced by this new probe, other more specific tests are needed.