Water-Soluble Dual-Channel Fluorescent Probe for Sensitive Detection of Biothiols In Vitro and In Vivo.

Benefiting from high spatiotemporal resolution, deep tissue penetration, and excellent sensitivity, fluorescence imaging technology has been widely applied in cancer diagnosis and treatment. In recent years, a large number of fluorescent probes for monitoring the levels of endogenous biothiols have been reported, which have significant implications for cancer diagnosis and treatment. However, most probes still suffer from poor biological compatibility and easy attachment by the environment. This work presents the development of a water-soluble dual-channel fluorescent probe, named MAL-NBD, for sensitively detecting biothiols. Nonfluorescent MAL-NBD is transformed into fluorescent groups MAL and NBD-SR/NR through nucleophilic substitution by biologically active thiols, producing dual-channel fluorescence signals for precise detection of biologically active thiols. Taking advantage of the excellent biocompatibility and low biotoxicity, MAL-NBD is successfully used for imaging HeLa cancer cells and zebrafish larvae, promoting its potential application for the precise detection of biological thiols involved in physiological and pathological processes.

Synthesis of a novel p-hydroxycinnamic amide with anticancer capability and its interaction with human serum albumin.

In the present study, a novel p-hydroxycinnamic amide (E)-3-(4-hydroxyphenyl)-N-(4-(N-(5-meth oxypyrimidin-2-yl)-sulfamoyl)phenyl)acrylamide (HMSP) was synthesized and confirmed. In vitro cytotoxic assays indicated that HMSP was able to inhibit the proliferation of various cancer cell lines. The interaction between HMSP and human serum albumin (HSA) was examined by fluorescence, UV-Vis and circular dichroism (CD) spectra, in addition to molecular simulation. The fluorescence and UV-Vis spectra data indicated that the binding of HMSP with HSA was a static process. According to the fluorescence quenching calculation, the corresponding thermodynamic parameters, bimolecular quenching rate constant and apparent quenching constants were calculated. Van der Walls forces and hydrogen bonds were vital in the binding of HMSP on HSA. The distances between HSA and its derivatives were obtained. Furthermore, competitive experiments and molecular modeling results suggested that the binding of the compound on HSA mainly occurred in site I (sub-domain IIA). Changes in HSA conformation were observed from synchronous fluorescence and CD spectra, which were further investigated by molecular dynamic simulations.