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Spectroscopy
Volume 24 (2010), Issue 1-2, Pages 137-142
http://dx.doi.org/10.3233/SPE-2010-0415

Interactions of the β-blocker drug, propranolol, with detergents, β-cyclodextrin and living cells studied using fluorescence spectroscopy and imaging

R. H. Bisby,1,4 S. W. Botchway,2 A. G. Crisostomo,1,5 J. Karolin,3 A. W. Parker,2 and L. Schröder1

1School of Environment and Life Sciences, Peel Building, University of Salford, Salford, UK
2Lasers for Science Facility, Central Laser Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, UK
3Department of Physics, SUPA, University of Strathclyde, Glasgow, UK
4School of Environment and Life Sciences, Peel Building, University of Salford, Salford M5 4WT, UK
5MRC Laboratory of Molecular Biology, Hills Road, Cambridge, CB2 0QH, UK

Copyright © 2010 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Interactions of the β-blocker drug, propranolol, with amphipathic systems have been studied using fluorescence spectroscopy. The results show a strong binding of propranolol with micelles of sodium dodecyl sulfate revealed through changes in the fluorescence spectrum and an increase in fluorescence lifetime. Quenching of propranolol fluorescence by iodide is used to demonstrate interaction with β-cyclodextrin. At high concentrations, self-quenching of propranolol fluorescence was also observed with κq=2.5×109 dm3 mol–1 s–1. Two-photon excited (630 nm) fluorescence lifetime imaging of propranolol in cells showed propranolol to be widely distributed in the cell cytoplasm, with fluorescence lifetimes shorter than in solution. The results suggest that intracellular propranolol is mainly confined within the aqueous cytoplasm and rather than membrane associated.