The measurement of the phosphorescence and singlet oxygen fluorescence time-resolved waveforms of Photofrin(II)® and Talaporfin Sodium with pulsed excitation

In order to investigate the interaction between the triplet state T ₁ and ground state oxygen ³O₂ during pulsed excitation photodynamic therapy (PDT), we measured the phosphorescence and singlet oxygen ¹O₂ fluorescence timeresolved waveform. The phosphorescence time-resolved waveform from clinical photosensitizers has not been obtained because this signal was buried in the photosensitizer fluorescence. We constructed the experimental setup with a spectral and temporal filter to select the phosphorescence signals from the Photofrin(II)® and Talaporfin sodium solution. The lifetimes and spectrums of the measured luminescence coincided with the phosphorescence characteristics, respectively. We obtained the phosphorescence time-resolved waveforms from the clinical photosensitizer solutions successfully. The ₁O₂ fluorescence time-resolved waveforms from these photosensitizers were measured with an IR-PMT with a photon counter. The fluorescence time-resolved waveforms of each photosensitizer were also obtained by the authors. We could consequently describe sequential generation of three time-resolved waveforms throughout the photosensitive reaction in the clinical photosensitizers. We think we may evaluate the photoseisitizer characteristics by these waveforms.