Lipophilic ruthenium complexes with tuned cell membrane affinity and photoactivated uptake

• Ruthenium dipyridophenazine (dppz) complexes are virtually non-emissive in aqueous solutions but show strong luminescence in hydrophobic environments, making them interesting as molecular probes in cellular imaging. We show by luminescence spectroscopy that by substituting the dppz ligand with alkyl ether chains of increasing length the complexes can be tuned from preferential intercalation into DNA to insertion in model phospholipid membranes Confocal laser scanning microscopy (CLSM) on methanol fixed CHO-K1 cells show an analogous distribution in the cell, where the least hydrophobic complex exclusively stains the nucleus whereas the more hydrophobic ones seem to predominantly stain membrane structures in the cytoplasm In live cells CLSM show that initially only the more hydrophobic derivatives stain the plasma membrane However, brief further exposure to the laser light causes permeabilization of the membrane and accumulation of extracellular ruthenium complexes in internal cellular structures, similarly to the distribution found in fixed cells. (C) 2010 Elsevier B V All rights reserved

Subject headings

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Keyword

dna

mechanism

scanning microscopy

Ruthenium dipyridophenazine complex

Membrane binding

light-switch

probes

Confocal laser

Photoactivated cellular uptake

polypyridyl complex

liposome membranes

Luminescent cellular probes

Emission spectroscopy

Publication and Content Type

art (subject category)

ref (subject category)