Yaseen Mohammad A, Yu Jie, Jung Bongsu, Wong Michael S, Anvari Bahman
Department of Bioengineering, Rice University, Houston, Texas, USA.
Mol Pharm. 2009 Sep-Oct;6(5):1321-32. doi: 10.1021/mp800270t.
Indocyanine green (ICG) is a fluorescent probe used in various optically mediated diagnostic and therapeutic applications. However, utility of ICG remains limited by its unstable optical properties and nonspecific localization. We have encapsulated ICG within electrostatically assembled mesocapsules (MCs) to explore its potential for targeted optical imaging and therapy. In this study, we investigate how the surface coating and size of the MCs influences ICG's biodistribution in vivo. ICG was administered intravenously to Swiss Webster mice as a free solution or encapsulated within either 100 nm diameter MCs coated with dextran; 500 nm diameter MCs coated with dextran; or 100 nm diameter MCs coated with 10 nm ferromagnetic iron oxide nanoparticles, themselves coated with polyethylene glycol. ICG was extracted from harvested blood and organs at various times and its amount quantified with fluorescence measurements. MCs containing ICG accumulated in organs of the reticuloendothelial system, namely, the liver and spleen, as well as the lungs. The circulation kinetics of ICG appeared unaffected by encapsulation; however, the deposition within organs other than the liver suggests a different biodistribution mechanism. Results suggest that the capsules' coating influences their biodistribution to a greater extent than their size. The MC encapsulation system allows for delivery of ICG to organs other than the liver, enabling the potential development of new optical imaging and therapeutic strategies.
吲哚菁绿（ICG）是一种用于各种光介导诊断和治疗应用的荧光探针。然而，ICG的效用仍然受到其不稳定光学性质和非特异性定位的限制。我们将ICG封装在静电组装的介孔胶囊（MCs）中，以探索其在靶向光学成像和治疗方面的潜力。在本研究中，我们研究了MCs的表面涂层和尺寸如何影响ICG在体内的生物分布。将ICG作为游离溶液静脉注射给瑞士韦伯斯特小鼠，或者将其封装在直径为100nm、涂有葡聚糖的MCs中；直径为500nm、涂有葡聚糖的MCs中；或者直径为100nm、涂有10nm铁磁性氧化铁纳米颗粒（其本身又涂有聚乙二醇）的MCs中。在不同时间从采集的血液和器官中提取ICG，并通过荧光测量对其含量进行定量。含有ICG的MCs在网状内皮系统的器官，即肝脏、脾脏以及肺中积累。ICG循环动力学似乎不受封装影响；然而，在肝脏以外器官中的沉积表明存在不同的生物分布机制。结果表明，胶囊的涂层对其生物分布的影响程度大于其尺寸。MC封装系统允许将ICG递送至肝脏以外的器官，从而有可能开发新的光学成像和治疗策略。
