Li Ruibin, Wu Ren'an, Zhao Liang, Qin Hongqiang, Wu Jianlin, Zhang Jingwen, Bao Ruyi, Zou Hanfa
Division of NanoMedicine, Department of Medicine, University of California, Los Angeles, CA 90095, USA.
Nanotechnology. 2014 Dec 12;25(49):495102. doi: 10.1088/0957-4484/25/49/495102. Epub 2014 Nov 20.
Functionalized carbon nanotubes (f-CNTs) have been widely used in bio-medicine as drug carriers, bio-sensors, imaging agents and tissue engineering additives, which demands better understanding of their in vivo behavior because of the increasing exposure potential to humans. However, there are limited studies to investigate the in vivo biodistribution and elimination of f-CNTs. In this study, superparamagnetic iron oxides (SPIOs) were used to label oxidized multiwalled carbon nanotubes (o-MWCNTs) for in vivo distribution study of o-MWCNTs by magnetic resonance imaging (MRI). SPIO labeled o-MWCNTs (((SPIO))o-MWCNTs) were prepared by a hydrothermal reaction process, and characterized by TEM, XRD and magnetometer. ((SPIO))o-MWCNTs exhibited superparamagnetic property, excellent biocompatibility and stability. The intravenously injected ((SPIO))o-MWCNTs were observed in liver, kidney and spleen, while the subcutaneously injected ((SPIO))o-MWCNTs could be only detected in sub mucosa. Most of the intravenously injected ((SPIO))o-MWCNTs could be eliminated from liver, spleen, kidney and sub mucosa on 4 d post injection (P.I.). However, the residual o-MWCNTs could induce 30-40% MRI signal-to-noise ratio changes in these tissues even on 30 d P.I. This in vivo biodistribution and elimination information of o-MWCNTs will greatly facilitate the application of f-CNT based nanoproducts in biomedicine. In addition, the magnetic labeling method provides an approach to investigate the in vivo biodistribution and clearance of other nanomaterials.
功能化碳纳米管（f-CNTs）作为药物载体、生物传感器、成像剂和组织工程添加剂已在生物医学中广泛应用，鉴于人类接触其可能性的增加，这就需要更好地了解它们在体内的行为。然而，关于f-CNTs在体内生物分布和消除的研究有限。在本研究中，超顺磁性氧化铁（SPIOs）被用于标记氧化多壁碳纳米管（o-MWCNTs），以通过磁共振成像（MRI）研究o-MWCNTs的体内分布。通过水热反应过程制备了SPIO标记的o-MWCNTs（((SPIO))o-MWCNTs），并通过透射电子显微镜（TEM）、X射线衍射（XRD）和磁力计对其进行了表征。((SPIO))o-MWCNTs表现出超顺磁性、优异的生物相容性和稳定性。静脉注射的((SPIO))o-MWCNTs在肝脏、肾脏和脾脏中被观察到，而皮下注射的((SPIO))o-MWCNTs仅能在黏膜下层被检测到。大部分静脉注射的((SPIO))o-MWCNTs在注射后4天（P.I.）可从肝脏、脾脏、肾脏和黏膜下层消除。然而，即使在注射后30天，残留的o-MWCNTs仍可在这些组织中引起30 - 40%的MRI信噪比变化。o-MWCNTs的这种体内生物分布和消除信息将极大地促进基于f-CNT的纳米产品在生物医学中的应用。此外，磁性标记方法为研究其他纳米材料的体内生物分布和清除提供了一种途径。
