Live-cell fluorescence imaging: assessment of thioflavin T uptake in human epidermal carcinoma cells.

Thioflavin T (ThT), a positively charged heterocyclic small molecule, is a widely used fluorescent marker of amyloid pathophysiology to confirm the cause of death in brain tissue of Alzheimer's disease (AD) patients. Literature precedents indicate that current positron emission tomography (PET) agents, such as C-PIB and F-flutemetamol, share significant structural similarity with ThT, a lipophilic dye which does not traverse the blood-brain barrier (BBB) to enable the detection of Aβ plaques . While vital for maintaining normal physiology and healthy brain function, the BBB comprises brain endothelial cells sealed paracellular protein complexes, bound by an extracellular matrix forming tight junctions thus controlling the delivery of molecules into the brain.