Effects of PDT on the in vivo absorption properties of AlS2Pc in tumor-bearing mice

Time-resolved reflectance spectroscopy was used to investigate the effects of photodynamic irradiation on the in vivo absorption properties of disulphonated Aluminum Phthalocyanine (AlS2Pc) in tumor-bearing mice. Mice bearing tumors injected either intramuscularly or intradermally were administered with 5 mg/kg body weight of AlS2Pc. Uptake times of 3 h and 12 h were examined. Absorption spectra were measured from 610 to 700 nm before, during and after the irradiation. The administration of a therapeutic light dose causes a blue-shift and a reduction in the drug absorption, which are more marked 3 h than 12 h after drug injection.