Nanoscience and Nanotechnology Research Center, Research Organization for the 21st Century, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570, Japan.
Nanotechnology. 2010 Jun 18;21(24):245104. doi: 10.1088/0957-4484/21/24/245104. Epub 2010 May 25.
Gold nanoparticles (Au NPs) are a potential x-ray computed tomography (CT) contrast agent. A biocompatible and bioinactive surface is necessary for application of gold nanoparticle to CT imaging. Polyethylene glycol (PEG)-attached dendrimers have been used as a drug carrier with long blood circulation. In this study, the Au NPs were grown in the PEGylated dendrimer to produce a CT contrast agent. The Au NPs were grown by adding gold ions and ascorbic acid at various equivalents to the Au NP-encapsulated dendrimer solution. Both size and surface plasmon absorption of the grown Au NPs increased with adding a large number of gold ions. The x-ray attenuation of the Au NPs also increased after the seeded growth. The Au NPs grown in the PEG-attached dendrimer at the maximum under our conditions exhibited a similar CT value to a commercial iodine agent, iopamidol, in vitro. The Au NP-loaded PEGylated dendrimer and iopamidol were injected into mice and CT images were obtained at different times. The Au NP-loaded PEGylated dendrimer achieved a blood pool imaging, which was greater than a commercial iodine agent. Even though iopamidol was excreted rapidly, the PEGylated dendrimer loading the grown Au NP was accumulated in the liver.
金纳米粒子（Au NPs）是一种潜在的 X 射线计算机断层扫描（CT）造影剂。为了将金纳米粒子应用于 CT 成像，需要具有生物相容性和非生物活性的表面。聚乙二醇（PEG）接枝树状大分子已被用作具有长血液循环的药物载体。在这项研究中，将 Au NPs 生长在 PEG 化树状大分子中，以产生 CT 造影剂。通过向 Au NP 包裹的树状大分子溶液中添加不同当量的金离子和抗坏血酸来生长 Au NPs。随着添加大量金离子，生长的 Au NPs 的尺寸和表面等离子体吸收均增加。种子生长后，Au NPs 的 X 射线衰减也增加。在我们的条件下，PEG 接枝树状大分子中生长的 Au NPs 在最大程度下表现出与体外商业碘造影剂碘帕醇相似的 CT 值。将负载 Au NPs 的 PEG 化树状大分子和碘帕醇注入小鼠体内，并在不同时间获得 CT 图像。负载 Au NPs 的 PEG 化树状大分子实现了血池成像，其效果大于商业碘造影剂。尽管碘帕醇迅速排泄，但负载生长的 Au NP 的 PEG 化树状大分子在肝脏中积累。
