title: In vivo detection of magnetic labeled oxidized multi-walled carbon nanotubes by magnetic resonance imaging.
abstract: 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.
authors.affiliation: Division of NanoMedicine, Department of Medicine, University of California, Los Angeles, CA 90095, USA. ruibinli@hotmail.com
authors.forename: Ruibin
authors.initials: R
authors.lastname: Li
authors.forename: Ren'an
authors.initials: R
authors.lastname: Wu
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.forename: Hongqiang
authors.initials: H
authors.lastname: Qin
authors.forename: Jianlin
authors.initials: J
authors.lastname: Wu
authors.forename: Jingwen
authors.initials: J
authors.lastname: Zhang
authors.forename: Ruyi
authors.initials: R
authors.lastname: Bao
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000032:analysis / Q000737:chemistry; D002478:Cells, Cultured; D005290:Ferric Compounds; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000032:analysis* / Q000737:chemistry* / Q000648:ultrastructure; D008297:Male; D008422:Materials Testing; D037742:Nanotubes, Carbon / Q000032:analysis* / Q000737:chemistry* / Q000648:ultrastructure; D017208:Rats, Wistar; D013154:Spleen / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; D037742:Nanotubes, Carbon; C000499:ferric oxide