| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1230068 | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2015 | 10 Pages |
•Zinc mono carboxy phenoxy phthalocyanine is coordinated to ascorbic acid.•The conjugate shows improved photophysical behavior.•However ascorbic acid suppresses the photodynamic therapy activity.
Zinc mono carboxy phenoxy phthalocyanine (1) was chemical modified with ascorbic acid via an ester bond to give ZnMCPPc-AA (2). Complexes 2 and 1 were coordinated to single walled carbon nanotubes via π–π interaction to give ZnMCPPc-AA-SWCNT (3) and ZnMCPPc-SWCNT (4) respectively. Complexes 2, 3 and 4 showed better photophysical properties: with improved triplet lifetimes and quantum yields, and singlet oxygen quantum yields when compared to 1 alone. The photodynamic therapy activities of complexes 1, 2, 3 and 4 were tested in vitro on MCF-7 breast cancer cells. Ascorbic acid suppresses the photodynamic therapy effect of 1, due to its ability to reduce oxidative DNA damage as a result of its potent reducing properties. The highest phototoxicity was observed for 4 which resulted in 77% decrease in cell viability, followed by 3 which resulted in 67% decrease in cell viability. This shows the importance of combination therapy, where the phthalocyanines are the photodynamic therapy agents and single walled carbon nanotubes are the photothermal therapy agents.
Graphical abstractZinc mono carboxy phenoxy phthalocyanine was linked to ascorbic acid with improved photophysical properties. Ascorbic acid was however found to suppress the photodynamic therapy of cancer activity of the phthalocyanine.Figure optionsDownload full-size imageDownload as PowerPoint slide
