Intracellular Distribution of Fluorescent Copper and Zinc Bis(thiosemicarbazonato) Complexes Measured with Fluorescence Lifetime Spectroscopy

Abstract

The intracellular distribution of fluorescently labeled copper and zinc bis(thiosemicarbazonato) complexes was investigated in M17 neuroblastoma cells and primary cortical neurons with a view to providing insights into the neuroprotective activity of a copper bis(thiosemicarbazonato) complex known as CuII(atsm). Time-resolved fluorescence measurements allowed the identification of the CuII and ZnII complexes as well as the free ligand inside the cells by virtue of the distinct fluorescence lifetime of each species. Confocal fluorescent microscopy of cells treated with the fluorescent copper(II)bis(thiosemicarbazonato) complex revealed significant fluorescence associated with cytoplasmic punc..