Synthesis, Spectral Properties and Cell Assays of Novel Fluorophore-Modified β-Cyclodextrin Derivatives

Three novel fluorophore-modified β-cyclodextrin derivatives, 6-deoxy-6-O-[4-difluoro-4-bora-3a,4a-diaza-s-indacene]-β-cyclodextrin (1a), 6-deoxy-6-O-[4-piperidine-N-(p-hydroxyphenyl)-1,8-naphthalimide]-β-cyclodextrin (2a), and 6-deoxy-6-O-(4-methyl-7-hydroxycoumarin)-β-cyclodextrin (3a) were synthesized and characterized. The absorption and emission spectra of these novel compounds above were studied in aqueous solution. Moreover, the cell uptake of compound 1a modified by fluorophore 4,4-difluoro-8-(4-hydroxyphenyl)-4-bora-3a,4a-diaza-s-indacene (1) was evaluated in vitro employing human glioma BT-325 cells through fluorescence cell imaging and flow cytometry detection. The results indicate that studied β-cyclodextrin derivatives are able to enter BT-325 cells and have a certain ability to go through the blood-brain barrier (BBB), which suggests their potential application in the drug delivery system by permeating through the BBB to enter the central nervous systems (CNS).