Endovascular photodynamic therapy to inhibit intimal hyperplasia

据报道，光动力疗法可以抑制血管内膜增生的发展。在这项研究中，我们研究了第二代光敏剂L天冬氨酸氯乙酯(NPe6)在兔动脉模型中的时程动脉蓄积和分布。用高效液相色谱法测定动脉血中NPe6的浓度，用自行研制的荧光图像分析系统观察NPe6的荧光。NPe6在球囊损伤动脉和动脉粥样硬化动脉的峰值浓度明显高于正常动脉。为了使激光均匀地照射到血管壁，我们使用了新研制的圆柱形扩散球囊激光纤维。用球囊导管通过兔右髂动脉造成损伤。血管内皮细胞NPe6-PDT显示血管内皮细胞在低剂量激光照射后2天完全耗尽。PDT后2周，血管内皮细胞增殖明显受到抑制。在本实验模型中，NPe6对损伤动脉的血管内PDT有抑制作用，可能对动脉介入后形成增生性病变有一定的抑制作用。

Photodynamic therapy reportedly inhibits the development of intimal hyperplasia. In this study, we examined time-course arterial accumulation and distribution of a second generation photosensitizer mono-l-aspartyl chlorin e6 (NPe6) in rabbit arterial models. Arterial NPe6 concentration was measured by HPLC and epifluorescence of NPe6 was observed by our developed epifluorescence image analysis system. The peak values of NPe6 concentration in balloon injured arteries and atherosclerotic arteries were significantly high when compared with the normal arteries.For homogeneous radial laser irradiation to the vessel wall, we used newly developed cylindrical diffusing balloon laser fiber. Injuries were induced by pulling a balloon catheter through the right iliac artery of rabbits. The arteries were harvested at two days and 2 weeks.Endovascualr NPe6-PDT showed complete depletion of smooth muscle cells using low-dose laser at 2 days. Intimal hyperplasia was significantly inhibited at 2 weeks after PDT.Endovascular PDT of injured artery using NPe6 can inhibit intimal hyperplasia in this experimental model and may be effective in inhibiting to form hyperplastic lesions after arterial interventions.