In vitro experimental photodynamic diagnosis of artery atherosclerosis

摘要

Background: Although there are several methods for atherosclerosis detection available, none of them seems to be accurate enough to identify the vulnerable atherosclerotic plaque. Photodynamic diagnosis (PDD) and therapy (PDT) - a new method evaluated for neoplasms treatment is a modem approach to detecting and treating atherosclerosis. Aim: The purpose of this study was to asses in vitro the capability of PDD with use of chloirn e6 to recognize atherosclerotic plaque and its usefulness as a feedback system for photoangioplasty treatment. Methods: 30 specimens of human aorta. The samples were soaked with chlorin e6 and then washed out. The luminescence spectra were then collected. All samples were examined with light microscopy. Results: Tissue fluorescence is seen as green light. We noted a very strong red fluorescence of chlorin e6 originating from lipid reach plaque. We established a quantitative factor which would be the ratio R of chlorin e6 red intensity in its 660 nm maximum compared to the area of green luminescence centred at 515 nm. The highest value of the ratio was reached at atheromatous samples, then calcified and normal ones R_2=3.51 +- 0.62, R_3=1.63 +- 0.31, R_1=1.51+- 0.15 respectively . Statistically significant difference was noted between group two and one and between group two and three R_2=3.51 +- 0.62 vs. R_3=1.63 +- 0.31 (p<0,05); R_2=3.51 +- 0.62 vs. R_1=1.51 +- 0.15 (p< 0.05) respectively. Conclusions: The following in vitro study confirms that photosensitizer chlorin e6 accumulates within atheromatous plaque. It may be a specific tool for atheromatous and normal or calcified segments discrimination. The advantage of the above method is a possibility of a real time imaging followed by targeted therapy of various forms and stages of atherosclerosis.