Li C, Yu D, Kan Z, Yang D J, Tansey W, Kuang L R, Wallace S
Department of Diagnostic Radiology, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
Acad Radiol. 1996 Jun;3(6):500-6. doi: 10.1016/s1076-6332(96)80010-9.
A biodegradable radiopaque particulate contrast agent formulated from cyclic carbonate of ioxilan (IXC), which is a prodrug of nonionic water-solubel contrast ioxilan, recently has been developed. This contrast agent enhances liver attenuation and is cleared from the body as ioxilan. In the current study, we tested whether the biodistribution of IXC particles would be affected by the characteristics of particles.
IXC nanoparticles (average diameter = 290 nm) and IXC microparticles (average diameter = 1.7 mm) were prepared, characterized, and injected intravenously (i.v.; 50 mg I/kg body weight) into rats. Two sensitive, reproducible analytic methods--inductively coupled plasma-mass spectrometry (ICP-MS) and high-performance liquid chromatography (HPLC)- were used to quantify tissue iodine and ioxilan concentrations.
Both IXC nanoparticles and microparticles were taken up in the liver and spleen. The IXC nanoparticles remained in the liver at high concentrations for 6 hr and were slowly cleared. They also gave a high blood iodine concentration in the first 5 min after i.v. injection, suggesting their potential use as a blood-pool imaging agent. Unlike the nanoparticles, the microparticles had a significantly lower uptake by the kidney.
Because of reduced renal uptake, microparticles are a preferred macrophage imaging agent. Biodegradable radiopaque particles may be used either as blood-pool imaging agents or as macrophage imaging agents depending on their size and distribution characteristics. The ICP-MS and HPLC methods are useful for biodistribution studies of iodinated contrast agents.
一种由碘克沙醇（IXC）的环状碳酸酯配制而成的可生物降解的放射性不透明微粒造影剂已被研发出来，碘克沙醇是一种非离子水溶性造影剂碘克沙醇的前体药物。这种造影剂可增强肝脏的衰减，并以碘克沙醇的形式从体内清除。在本研究中，我们测试了IXC颗粒的生物分布是否会受到颗粒特性的影响。
制备、表征了IXC纳米颗粒（平均直径 = 290 nm）和IXC微粒（平均直径 = 1.7 mm），并将其静脉注射（50 mg I/ kg体重）到大鼠体内。使用两种灵敏、可重复的分析方法——电感耦合等离子体质谱法（ICP-MS）和高效液相色谱法（HPLC）——来定量组织中的碘和碘克沙醇浓度。
IXC纳米颗粒和微粒均被肝脏和脾脏摄取。IXC纳米颗粒在肝脏中高浓度停留6小时，并被缓慢清除。它们在静脉注射后的前5分钟也使血碘浓度升高，表明它们有作为血池显像剂的潜在用途。与纳米颗粒不同，微粒在肾脏中的摄取明显较低。
由于肾脏摄取减少，微粒是一种更优的巨噬细胞显像剂。可生物降解的放射性不透明颗粒可根据其大小和分布特征用作血池显像剂或巨噬细胞显像剂。ICP-MS和HPLC方法可用于碘化造影剂的生物分布研究。
