Abstract
Talaporfin sodium mediated photosensitization effects induced by pulsed (FWHM: 8.7ns, 40Hz) or continuous wave (CW) irradiation were investigated in serum containing solution, in vitro, and in vivo. The singlet oxygen luminescence in the solution under the pulsed irradiation was significantly reduced to about 40% of the CW irradiation at the fluence rate of 200mW/cm2. The oxygen consumption in the solution and the photocytotoxicity against macrophage-like cells under pulsed irradiation was significantly decreased when the fluence rate increased from 20 to 400mW/cm2, while the these fluence rate dependences were minor under CW irradiation. The obtained fluence rate dependences of the singlet oxygen luminescence, oxygen consumption, and photocytotoxicity were consistently correlated to each other. The pulsed irradiation PDT on the rat subcutaneous prostate tumor treated at 400mW/cm2 and 100J/cm2 irradiation demonstrated the superficial tumor preservation. This preservation could not be explained the irradiation condition dependence of the obtained photocytotoxicity in vitro.
