Lawaczeck R, Bauer H, Frenzel T, Hasegawa M, Ito Y, Kito K, Miwa N, Tsutsui H, Vogler H, Weinmann H J
Schering AG, Research Laboratories, Berlin, Germany.
Acta Radiol. 1997 Jul;38(4 Pt 1):584-97. doi: 10.1080/02841859709174391.
To evaluate the physical and pharmacological profiles of SH U555A, a suspension of magnetic iron oxide particles that is designed to enhance the visualization of liver tumors and metastases.
Chemical and physical methods were used to characterize the size and structure of these magnetic iron oxide particles in aqueous solution. The biodistribution and pharmacokinetics of the particles were studied in mice, rats and dogs. The imaging efficacy of the particles was demonstrated by MR imaging in rat liver tumors
The SH U555A particles consist of low-molecular-weight carboxydextran-coated iron oxides predominantly of the gamma-Fe2O3 form with a hydrodynamic diameter ranging from 57-59 nm and strong T2 relaxivity of 164 liters x mmol(-1) x s(-1) (water, 0.47 T). In rats the particles exhibited a dose-dependent half-life of between 2 and 3 days in the liver at a dose of 20 micromol Fe/kg and a shorter half-life at lower doses. No major side effects were found. In a rat tumor model the tumor-to-liver contrast was markedly improved after i.v. administration of SH U555A. At a dose of 14 micromol Fe/kg the half-maximal contrast-effect was obtained even in nonoptimized T1-weighted spin-echo images.
SH U555A is a superparamagnetic MR contrast agent for i.v. administration and has substantial potential for the demarcation of liver tumors.
评估SH U555A的物理和药理学特性，SH U555A是一种磁性氧化铁颗粒悬液，旨在增强肝肿瘤和转移灶的可视化。
采用化学和物理方法对水溶液中这些磁性氧化铁颗粒的大小和结构进行表征。在小鼠、大鼠和犬中研究了颗粒的生物分布和药代动力学。通过大鼠肝肿瘤的磁共振成像证明了颗粒的成像效果。
SH U555A颗粒由低分子量羧基葡聚糖包被的氧化铁组成，主要为γ-Fe2O3形式，流体动力学直径为57 - 59 nm，T2弛豫率为164 L·mmol-1·s-1（水，0.47 T）。在大鼠中，剂量为20 μmol Fe/kg时，颗粒在肝脏中的半衰期呈剂量依赖性，为2至3天，较低剂量时半衰期较短。未发现重大副作用。在大鼠肿瘤模型中，静脉注射SH U555A后肿瘤与肝脏的对比度明显改善。在剂量为14 μmol Fe/kg时，即使在未优化的T1加权自旋回波图像中也能获得半数最大对比效应。
SH U555A是一种用于静脉注射的超顺磁性磁共振造影剂，在肝肿瘤的界定方面具有很大潜力。
