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Fig. 5 Concentration-dependent, light-stimulated cytotoxicity. Cells
were treated with EDANS-Dox at various concentrations in the dark
(open squares) or with UV light for 20 min (black diamonds). After 2 h,
the cells were washed with fresh media and allowed to grow for 72 h.
The fraction of surviving cells relative to no drug controls was
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In conclusion, we have developed a new and efficient
strategy for drug release based on photocaged permeability
(PCP). In this first report, we have focused on applying PCP to
the light-stimulated delivery of Dox into esophageal adeno-
carcinoma cells. In principle, the PCP approach could be
applied to any small, cell permeable molecule that has a free
amine, hydroxyl, or carboxylic acid group for attachment of
the veratryl-EDANS molecule. Further experiments will focus
on use of other light-scissile linkers that can operate at longer
wavelengths that are able to penetrate farther into tissues, as
well as the use of other molecules that block permeability.
The authors acknowledge financial support from the
American Cancer Society (IRG-73-001-34) and the Massey
Cancer Center. Flow cytometry and confocal microscopy were
supported in part by grants P30CA16059 and 5P30NS047463.
We thank Dr M. Bertino (VCU) and M. Foussekis (VCU)
for help in measuring light intensity, Dr J. Eshleman (Johns
Hopkins) for the JH-EsoAd1 cells, and Dr A. Cropp (VCU)
for helpful comments.
Notes and references
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c
This journal is The Royal Society of Chemistry 2012
Chem. Commun., 2012, 48, 4755–4757 4757