Selective removal of cholesteryl oleate through collagen films by MIR FEL

(Wrk-P-3-02)

K.Awazu, Y.Fukami, M.Heya, S.Nakai  

IFEL,Osaka University, Osaka, Japan

The laser angioplasty for cholesterol esters from the arteriosclerotic region has been particularly difficult because cholesterol bound to fatty acids enters the arterial tissues in a complicated manner. Accumulated cholesteryl oleate in the arterial wall is covered with endothelial cells. Therefore, normal endothelial cells should be damaged by the laser irradiation if the cells highly absorb the laser. We reported the results of experiments in which the FEL was tuned to 5.75 $\mu$m, a wavelength that corresponds to the stretching vibration mode of the ester bonds. Using the FEL, cholesterol ester was selectively removed without damaging albumin or the normal arterial wall. In this paper, a two-layer tissue model is proposed to evaluate the efficiency of removal between cholesteryl oleate as a model of atherosclerotic lesions and collagen as a model of endothelial cells when the tissue model is exposed to the 5.75 $\mu$m-FEL. The two-layer tissue model proposed here can be used to evaluate the removal effect between cholesteryl oleate as a model of atherosclerotic lesions and collagen as a model of endothelial cells when the tissue model is exposed to the 5.75 $\mu$m-FEL. As results, the amount of the photons which transmitted collagen layer was enough to remove cholesteryl oleate, and the cholesteryl oleate under the gelatin layer can be removed by the FEL about 15% without structure damage of the gelatin layer as a model of normal endothelial cells.