Light-sensitive intelligent drug delivery systems of coumarin-modified mesoporous bioactive glass

Functionalized mesoporous bioactive glasses (MBG) with photoactive coumarin demonstrates photo-responsive dimerization resulting in reversible gate operation Coumarin-modified MBG was used as a drug delivery carrier to investigate drug storage/release characteristics using phenanthrene as a model drug Irradiation with UV light (>310 nm) induced photo-dimerization of the coumarin-modified MBG, which led to the pores' closing with cyclobutane dimers and trapping of the guest phenanthrene in the mesopores However, irradiating the dimerized-coumarin-modified MBG with shorter wavelength UV light (similar to 250 nm) regenerates the coumarin monomer derivative by the photo-cleavage of cyclobutane chillers, such that trapped guest molecules are released from the mesopores The structural, morphological, textural and optical properties are well characterized by X-ray diffraction, transmission electron microscopy, N-2 adsorption/desorption, and UV-visible spectroscopy The results reveal that the MBG exhibits the typical ordered characteristics of the hexagonal mesostructure The system demonstrates great potential in light-sensitive intelligent drug delivery systems and disease therapy fields. Crown Copyright (C) 2010 Published by Elsevier Ltd on behalf of Acta Materialia Inc All rights reserved