Article

Functionalized single-walled carbon nanotubes containing traces of iron as new negative MRI contrast agents for in vivo imaging.

Unité de Pharmacologie Chimique et Génétique et d'Imagerie, Chimie ParisTech, Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, CNRS UMR 8151, Inserm U1022, Paris, F-75270 cedex, France.
Contrast Media & Molecular Imaging (Impact Factor: 3.33). 03/2012; 7(2):153-9. DOI: 10.1002/cmmi.474
Source: PubMed

ABSTRACT Single-walled carbon nanotubes (SWCNTs) containing traces of iron oxide were functionalized by noncovalent lipid-PEG or covalent carboxylic acid function to supply new efficient MRI contrast agents for in vitro and in vivo applications. Longitudinal (r(1)) and transversal (r(2)) water proton relaxivities were measured at 300 MHz, showing a stronger T(2) feature as an MRI contrast agent (r(2)/r(1)  = 190 for CO(2) H functionalisation). The r(2) relaxivity was demonstrated to be correlated to the presence of iron oxide in the SWNT-carboxylic function COOH, in comparison to iron-free ones. Biodistribution studies on mice after a systemic injection showed a negative MRI contrast in liver, suggesting the presence of the nanotubes in this organ until 48 h after i.v. injection. The presence of carbon nanotubes in liver was confirmed after ex vivo carbon extraction. Finally, cytotoxicity studies showed no apparent effect owing to the presence of the carbon nanotubes. The functionalized carbon nanotubes were well tolerated by the animals at the dose of 10 µg g(-1) body weight.

Download full-text

Full-text

Available from: Cyrille Richard, Nov 28, 2014
0 Followers
 · 
156 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: An efficient MRI T2-weighted contrast agent incorporating a potential liver targeting functionality was synthesized via the combination of superparamagnetic iron oxide (SPIO) nanoparticles with multiwalled carbon nanotubes (MWCNTs). Poly(diallyldimethylammonium chloride) (PDDA) was coated on the surface of acid treated MWCNTs via electrostatic interactions and SPIO nanoparticles modified with a potential targeting agent, lactose-glycine adduct (Lac-Gly), were subsequently immobilized on the surface of the PDDA-MWCNTs. A narrow magnetic hysteresis loop indicated that the product displayed superparamagnetism at room temperature which was further confirmed by ZFC (zero field cooling)/FC (field cooling) curves measured by SQUID. The multifunctional MWCNT-based magnetic nanocomposites showed low cytotoxicity in vitro to HEK293 and Huh7 cell lines. Enhanced T2 relaxivities were observed for the hybrid material (186 mm(-1) s(-1)) in comparison with the pure magnetic nanoparticles (92 mm(-1) s(-1)) due to the capacity of the MWCNTs to "carry" more nanoparticles as clusters. More importantly, after administration of the composite material to an in vivo liver cancer model in mice, a significant increase in tumor to liver contrast ratio (277%) was observed in T2 weighted magnetic resonance images.
    Biomaterials 10/2013; 35(1). DOI:10.1016/j.biomaterials.2013.09.079 · 8.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Carbon nanotubes (CNTs) consist of a family of carbon built nanoparticles, which biological effects depend on their physical characteristics and other constitutive chemicals (impurities and functions attached). CNTs are considered the 21(st) century material due to their unique physicochemical characteristics and applicability to industrial product. The use of these materials steadily increase worldwide and toxic outcomes need to be studied for each nanomaterial in depth to prevent adverse effects to humans and the environment. Entrance into the body is physical, and usually few nanoparticles enter the body; however, once there, they are persistent due to their limited metabolisms, so their removal is slow, and chronic cumulative health effects are studied. Oxidative stress is the main mechanism of toxicity but size, agglomeration, chirality as well as impurities and functionalization are some of the structural and chemical characteristic contributing to the CNTs toxicity outcomes. Among the many toxicity pathways, interference with cytoskeleton and fibrous mechanisms, cell signaling, membrane perturbations, and the production of cytokines, chemokines and inflammation are some of the effects resulting from exposure to CNTs. The aim of this review is to offer an up to date scope of the effects of CNTs on biological systems with attention to mechanisms of toxicity.
    Toxicology mechanisms and methods 11/2012; DOI:10.3109/15376516.2012.754534 · 1.37 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: PURPOSE: To establish a NIR (near infrared)-/pH-responsive and sustained-release tumor-targeting drug delivery system (SWNT-PEI/DOX/NGR). METHODS: Functionalized SWNTs with polymerised polymeric poly(ethylene imine) was linked NGR (Asn-Gly-Arg) tumor-targeting peptide by DSPE-PEG2000-Maleimide via the maleimide group and sulfhydryl group of cysteine, in the end, doxorubicin (DOX) was attached to SWNT-PEI to obtain a SWNT-PEI/DOX/NGR delivery system. RESULTS: The SWNT-PEI/DOX/NGR delivery system has significantly sustained-release effect and the slow release of DOX in normal tissues contribute to reduced systemic toxicity, while under 808 nm NIR laser irradiation or under lower pH environment the release of DOX can be accelerated. CONCLUSIONS: Due to hyperthermia sensitizer effect of DOX, chemo-photothermal exemplified by SWNT-PEI/DOX/NGR tumor-targeting delivery system is a promising approach to anticancer therapy in vivo or in vitro.
    Pharmaceutical Research 06/2013; 30(11). DOI:10.1007/s11095-013-1095-3 · 3.95 Impact Factor