Photophysical, electrochemical characteristics and cross-linking of STAT-3 protein by an efficient bifunctional agent for fluorescence image-guided photodynamic therapy
| Autor: | Yihui Chen, Robert A. Fenstermaker, Heinz Baumann, Suresh K. Pandey, Wenbo E, Karl M. Kadish, Shunichi Fukuzumi, Ravindra K. Pandey, Tracy Erin, Weiguo Liu, Michael J. Ciesielski, Kei Ohkubo, Allan R. Oseroff, Min Zhang |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Chlorophyll
STAT3 Transcription Factor Mice Nude Photochemistry Fluorescence Mice chemistry.chemical_compound Electron transfer Electrochemistry Animals Moiety Singlet state Physical and Theoretical Chemistry Cyanine Photosensitizing Agents Molecular Structure Singlet Oxygen Chemistry Singlet oxygen Glioma Carbocyanines Cross-Linking Reagents Intersystem crossing Photochemotherapy Oxidation-Reduction Neoplasm Transplantation Conjugate |
| Zdroj: | Photochemical & Photobiological Sciences. 6:1257-1267 |
| ISSN: | 1474-9092 1474-905X |
| Popis: | The photophysical, electrochemical and spectroscopic characteristics of a conjugate of 3-devinyl-3-(1'-hexyloxyethyl)pyropheophorbide-a (HPPH) and a cyanine dye have been investigated both as a linked conjugate and as individual components. A photoexcitation of the HPPH moiety of the conjugate results in electron transfer from the singlet excited state of HPPH (1HPPH*) to the cyanine dye as well as that from the cyanine dye to 1HPPH* and is followed in both cases by facile back electron transfer to the ground state as indicated by time-resolved fluorescence and transient absorption measurements. Intersystem crossing to the triplet excited state (3HPPH*) competes with the electron transfer and 3HPPH* is quenched by oxygen to produce singlet oxygen (1O2), leading to specific covalent cross-linking of the nonactivated signal transducer and activator of transcription (STAT-3). In contrast to excitation of the HPPH moiety, photoexcitation of the cyanine dye unit results in a strong emission at 875 nm, which can be used for efficient tumor imaging. Compared to HPPH alone, the presence of the cyanine dye moiety in the conjugate produces a significantly higher uptake in tumors than in skin. Thus, the HPPH-cyanine dye conjugate can be used as a dual tumor imaging and photodynamic therapy agent. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink