Anti‐Stokes fluorescence from endogenously formed protoporphyrin IX – Implications for clinical multiphoton diagnostics
| Autor: | Maria Smedh, Ann-Marie Wennberg, John Paoli, Mattias Goksör, Marica B. Ericson, Despina Kantere, Stina Guldbrand, Dag Hanstorp |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Skin Neoplasms
two-photon fluorescence microscopy Infrared Rays Protoporphyrins General Physics and Astronomy Photochemistry General Biochemistry Genetics and Molecular Biology aminolevulinic acid methylaminolevulinate Superficial basal cell carcinoma chemistry.chemical_compound Humans protoporphyrin IX General Materials Science Spectral analysis Tissue autofluorescence skin cancer Protoporphyrin IX Lasers Full Articles General Engineering General Chemistry Porphyrin Fluorescence Molecular Imaging Microscopy Fluorescence Multiphoton Spectrometry Fluorescence Multiphoton fluorescence microscope chemistry Biophysics anti-Stokes fluorescence Molecular imaging |
| Zdroj: | Journal of Biophotonics |
| ISSN: | 1864-0648 1864-063X |
| Popis: | Multiphoton imaging based on two-photon excitation is making its way into the clinics, particularly for skin cancer diagnostics. It has been suggested that endogenously formed protoporphyrin IX (PpIX) induced by aminolevulinic acid or methylaminolevulinate can be applied to improve tumor contrast, in connection to imaging of tissue autofluorescence. However, previous reports are limited to cell studies and data from tissue are scarce. No report shows conclusive evidence that endogenously formed PpIX increases tumor contrast when performing multiphoton imaging in the clinical situation. We here demonstrate by spectral analysis that two-photon excitation of endogenously formed PpIX does not provide additional contrast in superficial basal cell carcinomas. In fact, the PpIX signal is overshadowed by the autofluorescent background. The results show that PpIX should be excited at a wavelength giving rise to one-photon anti-Stokes fluorescence, to overcome the autofluorescent background. Thus, this study reports on a plausible method, which can be implemented for clinical investigations on endogenously formed PpIX using multiphoton microscopy. Three-dimensional multiphoton microscopy images obtained from a superficial basal cell carcinoma illustrating higher porphyrin contrast when anti-stokes excitation (710 nm) is used compared to two-photon excitation (810 nm). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text