Soluble cyanine dye/β-cyclodextrin derivatives: Potential carriers for drug delivery and optical imaging

Two soluble cyanine/beta-cyclodextrin derivatives have been synthesized under simultaneous ultrasound/microwave irradiation. UV-Vis, steady-state, time-resolved fluorescence and circular dichroism spectroscopies were used to evaluate their photophysical properties, as well as to study their complexation with the anticancer drug doxorubicin. Titration experiments were performed by monitoring corrected emission intensity. The analysis of fluorescence data provided stability constants for doxorubicin complexes with cyanine/beta-cyclodextrins which are 4 orders of magnitude greater than those reported for its complexation with native beta-cyclodextrin and one order greater than its association with DNA. The complexation has also been studied using Molecular Mechanics and Molecular Dynamics simulations. Both electrostatic and van de Waals binding energy contributions are important to system stabilization. The potential use of these systems as carriers has been evaluated via in vitro experiments on He La cells and by monitoring cell entrance via confocal laser scanning microscopy. (C) 2014 Elsevier Ltd. All rights reserved.