[Dynamics of photosensitizer in the cell]

1) Mono-L-aspartyl chlorin e6 is a photosensitizer with a molecular weight of 799.7 in which the double bond porphyrin ring has been reduced and an aspartic acid is attached to the propionic group at the carbon of the tetrapyrole ring via a peptide linkage. 2) The absorption spectrum of mono-L-aspartyl chlorin e6 is characterized by a Soret band at 398 nm and four Q bands located at 502, 530, 620, and 654 nm in PBS solution at pH 7.4. However, when it bound to serum albumin at ratios of more than 1:1 absorption peaks showed a red shift at 6 nm in the PBS solution. 3) Erythrocytes in the blood containing serum albumin and the same concentration of mono-L-aspartyl chlorin e6 were not lysed with the diode laser irradiation. 4) The concentration of mono-L-aspartyl chlorin e6 in mitochondria fraction of normal tissue decreased from 2 hours after intravenous injection. However, the concentration of mono-L-aspartyl chlorin e6 in mitochondria fraction of tumor increased during 4 hours after injection and then gradually decreased.