Conference Publication Details
Mandatory Fields
Gundy, S,Van der Putten, W,Shearer, A,Buckton, D,Ryder, AG,Ball, M,Kessel, D
OPTICAL METHODS FOR TUMOR TREATMENT AND DETECTION: MECHANISMS AND TECHNIQUES IN PHOTODYNAMIC THERAPY XII
Time-delayed fluorescence imaging of a porphycene derivative
2003
March
Published
1
()
Optional Fields
fluorescence lifetime tumour detection porphycene lifetime imaging autofluorescence PHOTODYNAMIC THERAPY PHOTOPHYSICAL PROPERTIES PHTHALOCYANINE TUMORS
152
161
Porphycenes are currently under investigation for use in Photodynamic therapy, which is a promising treatment for cancer. These materials, which display preferential uptake in cancerous cells, also exhibit high fluorescence yields, and can be used for tumour detection. Problems with steady-state fluorescence techniques such as background autofluorescence can be eliminated by the use of time-reolved techniques. Improved contrast can be obtained with time-resolved techniques because of the differing fluorescence lifetimes between autofluorescence and longer-living exogenous photosensitisers. An imaging system was constructed using a fast (200 ps) gated CCD camera and a pulsed 635 nm laser diode. A tissue phantom composed of polymethyl methacrylate (PMMA) with thirty-six wells of varying diameter and depth (10 mm to 1 mm) was assembled to test the system. The system was used to record images of a porphycene derivative within the wells at differing concentrations in an organic solvent. A tissue imitator was placed on top of the PMMA block at varying thickness. 10(-4) M zinc phthalocyanine tetrasulfonate was also placed on top of the block to mimic autofluorescence. The results indicate that the time-gated imaging system can prevent background excitation scatter and fluorescence from a shorter-lived fluorophore from distorting the fluorescence signal from a longer-lived photosensitiser.
Grant Details
Publication Themes