Fluorescence excitation efficiency is of great importance for photodynamic diagnosis. Because usually a difference in the interstitial pH between normal and tumor tissue occurs, it is necessary to assess the impact of pH on the fluorescence emission intensity of the photosensitizer meta-tetrahydroxyphenylchlorin (mTHPC) in this context. The results obtained by in vitro fluorescence measurements clearly indicate that pH values below 6 lead to a significant decrease in the fluorescence intensity. In the physiological range of pH 6.5–7.2, however, no pH dependence was found. Besides the decrease in the fluorescence intensity of mTHPC for pH < 6, changes in the spectral shape of the absorption were found. These changes can be utilized for “dual-wavelength ratio imaging,” using mTHPC as a pH-sensitive indicator with the excitation pair 405 nm/436 nm in the range of pH 3.5–6.
How to translate text using browser tools
1 April 2002
In Vitro Investigation on the pH Dependence of the Absorption and Fluorescence Properties of the Photosensitizer mTHPC
Andreas Zimmermann,
Monika Ritsch-Marte,
Herwig Kostron
ACCESS THE FULL ARTICLE
It is not available for individual sale.
This article is only available to subscribers.
It is not available for individual sale.
It is not available for individual sale.
Photochemistry and Photobiology
Vol. 75 • No. 4
April 2002
Vol. 75 • No. 4
April 2002