Abstract
Because of absorption band and tissue distribution properties, Mono L-aspartyl chlorin e6 (NPe6) is looked to as the useful photosensitizer for PDT. It is well known that NPe6 produces free radicals that induce tumor response. We performed quantitative analysis of NPe6 in saline using a diode laser (664nm). Our experiments showed the degradation rate of NPe6 solution of 3.13, 6.25, 12.5, 25, 50 and 100μmol/l exposed to 100mW and 100J light were around 60%. Otherwise the degradation rate of NPe6 solution of 12.5μmol/l exposed to 50, 100, 150mW and 100J light were also around 60%. When absorbance at 654nm decreased, the fluorescence of NPe6 at 664nm also decreased. Cleavage of the tetra pyrole structure was suggested.
Photobleaching of NPe6 did not depend on the initial concentration of NPe6 and laser power.
