No abstract

A rhodamine-based fluorescent lead probe reports on the labile lead pool within cells.

Lipid droplets are essential for cellular lipid storage, playing critical roles in cellular lipid metabolism. Although lipid droplets have drawn intense research in recent years, much remains to be uncovered about the roles of this organelle in biology. Lipid droplet indicators exhibiting large Stokes shifts and improved brightness are therefore in demand. We report two asymmetric BODIPY derivatives, BoL1 and BoL2 bearing a benzothiazole group at the 6‐position, which led to bathochromic shifts of 62 nm for BoL1 and 37 nm for BoL2 in fluorescence emission when compared to the reference molecules without the benzothiazole group. The incorporation of the benzothiazole moiety also resulted in a large Stokes shift of 40 nm. BoL1 and BoL2 have been demonstrated to operate as lipid droplet indicators in both confocal and STED imaging. BoL2 showed particularly good cellular retention and was further applied to explore the impact of cellular starvation on the trafficking of lipid droplets.

Copper participates in a range of critical functions in the nervous system in the human brain. Disturbances in brain copper content is strongly associated with neurological disease. For example, changes in the level and distribution of copper are reported in neuroblastoma, Alzheimer's disease and Lewy body disorders. There is a need for more sensitive techniques to measure intracellular copper levels to have a better understanding of the role of copper homeostasis in neuronal disorders. Here we report a reaction-based near-infrared (NIR) ratiometric fluorescent probe CyCu1 for imaging Cu2+ in biological samples. High stability and selectivity of CyCu1 enabled the probe to be deployed as a sensor in a range of systems, including SH-SY5Y and neuroblastoma cells. Furthermore, it can be used in plant cells, reporting copper added to Arabidopsis roots. We also used CyCu1 to explore Cu2+ levels and distribution in postmortem brain tissues from patients with the Lewy body disorder, Dementia with Lewy bodies (DLB). We found significant decreases in Cu2+ content in the nuclei, cytoplasm, neurons and extraneuronal space in the degenerating substantia nigra (SN) in DLB compared with healthy age-matched control tissues. These findings enhance our understanding of Cu2+ dysregulation in Lewy body disorders. Our probe also shows promise as a photoacoustic imaging agent, with potential for applications in bimodal imaging.