Fluorescent Image Analysis in a Mouse Tumor Model using Photosensitizer Mono-L-aspartyl Chlorin e6

Abstract

Mono-L-aspartyl chlorin e6 (NPe6) is a photosensitizer that possesses cancer affinity and is excreted from nomal tissues quickly.While NPe6 is exploitable for photodynamic therapy(PDT),it may affects the nomal tissues where NPe6 is over-remaining.To investigate the concentration of NPe6 in malignant tissues and nomal tissues in a mouse tumor model, we've made a fluorescent image analysis system by reconstructing an operating microscope. At 5 hours after administration of NPe6 20mg/kg body weight dose via the tail vein, both malignant and nomal tissues are excited at 405nm.The fluorescence of NPe6 is detected through a multilaminate interference filter that can select the fluorescent wavelength at 661nm or 664nm, -- the former is considered to be emitted mainly by free NPe6 and the latter by NPe6 which binds to albumin and the equivalent.The fluorescent intensity is changed into the concentration of NPe6 by a calibration curve.As a result,NPe6 accumulated in the malignant tissues 7 times as much as in the nomal one,that gives us much reliability upon PDT.