Zeimer R C, Khoobehi B, Peyman G, Niesman M R, Magin R L
Applied Physics Laboratory, Department of Ophthalmology, University of Illinois College of Medicine, Chicago 60612.
Invest Ophthalmol Vis Sci. 1989 Apr;30(4):660-7.
We are developing a new method of delivering substances locally and repeatedly in the retinal vasculature under external control. This delivery system is based on encapsulating the substance in heat-sensitive lipsomes, which are injected intravenously and lysed by a heat pulse delivered by a laser. The feasibility of using this system with dyes and creating a sharp dye front was tested in vitro and in vivo. The results indicate that the background fluorescence of intact liposomes is minimal but in contrast a dramatic increase in fluorescence is achieved where the dye is released. In vivo tests indicated that only the selected vascular branch fluoresced. Moreover, a sharp dye front could be obtained repeatedly and preserved over significant distances. The presence of a sharp dye front allowed measurements, in vitro, of blood velocity which correlated well (r = 0.985, P less than 0.001) with the average blood velocity values calculated from the known flow rate.
我们正在研发一种新方法，可在外部控制下于视网膜血管系统中局部且反复地递送物质。该递送系统基于将物质包裹于热敏脂质体中，脂质体通过静脉注射，并由激光发出的热脉冲使其裂解。使用该系统搭配染料并形成清晰染料前沿的可行性已在体外和体内进行了测试。结果表明，完整脂质体的背景荧光极小，但相比之下，染料释放处的荧光会显著增加。体内测试表明，仅选定的血管分支会发出荧光。此外，能够反复获得清晰的染料前沿，并在相当长的距离内保持。清晰染料前沿的存在使得在体外能够测量血流速度，该速度与根据已知流速计算出的平均血流速度值具有良好的相关性（r = 0.985，P小于0.001）。
