Synthesis and evaluation of near infrared fluorescent dye BPAD-2 for β-amyloid plaques

Abstract:

OBJECTIVE We synthesized a benzopyrane derivative BPAD-2 with push-pull electronic structure, and assessed its fluorescence properties, labelling ability for beta-amyloid plaques, and blood-brain barrier penetrating ability. METHODS BPAD-2 was synthesized by condensation reaction with 1-(2-hydroxy-phenyl)-ethanone as the primary reagent, and confirmed by 1H-NMR and MS. Fluorescence spectra were observed; fluorescence staining was performed to evaluate labelling ability for beta-amyloid plaques; fluorescent imaging was performed to evaluate blood-brain barrier penetrating ability. RESULTS The emission maximum of BPAD-2 in PBS was at 658 nm; BPAD-2 showed bright red labelling of beta-amyloid plaques; BPAD-2 penetrated the blood-brain barrier and peaked at 10 min postinjection and showed reasonable washout from the brain. CONCLSION BPAD-2 showed specific labelling of beta-amyloid plaques and had good blood-brain barrier penetrating ability.