Debefve E, Pegaz B, van den Bergh H, Wagnières G, Lange N, Ballini J-P
Ecole Polytechnique Fédérale de Lausanne, EPFL-ENAC-LPAS, 1015, Lausanne, Switzerland.
Angiogenesis. 2008;11(3):235-43. doi: 10.1007/s10456-008-9106-4. Epub 2008 Mar 7.
The aim of the present study was to monitor photodynamic angioocclusion with verteporfin in capillaries. Details of this process were recorded under a microscope in real-time using a high-sensitivity video camera. A procedure was developed based on intravenous (i.v.) injection of a light-activated drug, Visudyne, into the chorioallantoic membrane (CAM) of a 12-day-old chicken embryo. The effect of light activation was probed after 24 h by i.v. injection of a fluorescent dye (FITC dextran), and analysis of its fluorescence distribution. The angioocclusive effect was graded based on the size of the occluded vessels, and these results were compared with clinical observations. The time-resolved thrombus formation taking place in a fraction of the field of view was video recorded using a Peltier-cooled CCD camera. This vessel occlusion in the CAM model was reproducible and, in many ways, similar to that observed in the clinical use of verteporfin. The real-time video recording permitted the monitoring of platelet aggregation and revealed size-selective vascular closure as well as some degree of vasoconstriction. Platelets accumulated at intravascular junctions within seconds after verteporfin light activation, and capillaries were found to be closed 15 min later at the applied conditions. Larger-diameter vessels remained patent. Repetition of these data with a much more sensitive camera revealed occlusion of the treated area after 5 min with doses of verteporfin and light similar to those used clinically. Consequently, newly developed light-activated drugs can now be studied under clinically relevant conditions.
本研究的目的是监测维替泊芬在毛细血管中的光动力血管闭塞情况。使用高灵敏度摄像机在显微镜下实时记录该过程的细节。基于将光激活药物维速达尔静脉注射到12日龄鸡胚的尿囊膜中，开发了一种程序。24小时后，通过静脉注射荧光染料（异硫氰酸荧光素葡聚糖）并分析其荧光分布，来探究光激活的效果。根据闭塞血管的大小对血管闭塞效果进行分级，并将这些结果与临床观察结果进行比较。使用珀尔帖冷却的电荷耦合器件相机对视野的一部分中发生的时间分辨血栓形成进行视频记录。尿囊膜模型中的这种血管闭塞是可重复的，并且在许多方面与维替泊芬临床使用中观察到的情况相似。实时视频记录允许监测血小板聚集，并揭示了大小选择性血管闭合以及一定程度的血管收缩。维替泊芬光激活后数秒内血小板在血管内连接处聚集，在所应用的条件下，15分钟后发现毛细血管关闭。较大直径的血管保持通畅。使用灵敏度更高的相机重复这些数据显示，在使用与临床相似剂量的维替泊芬和光的情况下，5分钟后治疗区域出现闭塞。因此，现在可以在临床相关条件下研究新开发的光激活药物。
