Topics in Current Chemistry (2020) 378:15
1 3
GNTs to safely label porcine bone marrow-derived mesenchymal stem cells that displayed excellent image contrast in phantom MRI. Our group reported an interesting
and original application of SWCNTs to induce anisotropy in the diffusion of water
molecules in a phantom [103]. This work offers new perspectives for contrast generation in diffusion tensor magnetic resonance imaging, a powerful MRI technique
to explore the microstructure of healthy and pathological brain.
The near-infrared radiation (NIR) absorption property of CNTs [152] can also be
used to image their biodistribution in vivo. Yudasaka et al. [153] covered SWCNTs
with a biocompatible polymer, which accumulated in brown fat, providing an imaging tool to visualize the distribution of this tissue in a preclinical model. Kim et al.
[154] developed SWCNTs coated with gold and conjugated with antibody specific
to the lymphatic vessel endothelial hyaluronan receptor to image the lymphatic vessels in mice. They induced a temperature increase of CNTs by NIR absorption using
a laser beam and detected the nanotubes in the lymphatic vessels using photoacoustic and photothermal imaging. The NIR imaging techniques can also be combined
with NIR guide photothermal therapy [155]. In this work, Liang et al. functionalized
SWCNTs with polyethylene glycol to administrate them in BALB/c mice carrying
4T1 murine breast tumors in the inner knee. CNTs were directly injected on the primary tumor and visualized using photothermal imaging and MRI, not only in the
tumor but also in the nearest metastatic lymph.
CNTs can be functionalized with different radioisotopes like Y-86 [156], C-14
[157], I-125 [158], Tc-99 m [159] or Cu-64 [160], making them promising CAs for
nuclear medicine approaches. Al-Jamal and coworkers [161] used single-photon
emission computed tomography (SPECT)/computed tomography (CT) imaging to
study in vivo the internalization of three different MWCNTs radiolabeled with
111
In
(Fig. 9).
Furthermore, the particular features of carbon nanotubes make them good candidates to act as multimodal contrast agents with different imaging techniques.
4.2 Therapeutic Applications
Nanoparticles have revolutionized the field of drug delivery in the last two decades. Currently used therapeutic drugs suffer from low selectivity and low half-life,
making necessary it to give high doses to achieve the expected response, and thus
increasing undesirable side-effects. A proper and selective drug delivery system
would overcome most of these issues, and carbon nanotubes have been widely studied for this end [15].
As previously indicated, the nature of nanotubes permits a versatile chemistry allowing the attachment of drugs in a covalent or non-covalent manner with
an efficient drug-loading capacity. Besides, these nanostructures can be appropriately functionalized with different hydrophilic molecules to specifically recognize
the receptors overexpressed in the target cells, according to the alterations related
to the specific pathology to be treated [162]. So, the optimal functionalization of
CNTs make them promising drug-delivery systems in numerous therapies owing
to their achieved biocompatibility, suitable size, ability to penetrate the cells, and
196
Reprinted from the journal
1 3
GNTs to safely label porcine bone marrow-derived mesenchymal stem cells that displayed excellent image contrast in phantom MRI. Our group reported an interesting
and original application of SWCNTs to induce anisotropy in the diffusion of water
molecules in a phantom [103]. This work offers new perspectives for contrast generation in diffusion tensor magnetic resonance imaging, a powerful MRI technique
to explore the microstructure of healthy and pathological brain.
The near-infrared radiation (NIR) absorption property of CNTs [152] can also be
used to image their biodistribution in vivo. Yudasaka et al. [153] covered SWCNTs
with a biocompatible polymer, which accumulated in brown fat, providing an imaging tool to visualize the distribution of this tissue in a preclinical model. Kim et al.
[154] developed SWCNTs coated with gold and conjugated with antibody specific
to the lymphatic vessel endothelial hyaluronan receptor to image the lymphatic vessels in mice. They induced a temperature increase of CNTs by NIR absorption using
a laser beam and detected the nanotubes in the lymphatic vessels using photoacoustic and photothermal imaging. The NIR imaging techniques can also be combined
with NIR guide photothermal therapy [155]. In this work, Liang et al. functionalized
SWCNTs with polyethylene glycol to administrate them in BALB/c mice carrying
4T1 murine breast tumors in the inner knee. CNTs were directly injected on the primary tumor and visualized using photothermal imaging and MRI, not only in the
tumor but also in the nearest metastatic lymph.
CNTs can be functionalized with different radioisotopes like Y-86 [156], C-14
[157], I-125 [158], Tc-99 m [159] or Cu-64 [160], making them promising CAs for
nuclear medicine approaches. Al-Jamal and coworkers [161] used single-photon
emission computed tomography (SPECT)/computed tomography (CT) imaging to
study in vivo the internalization of three different MWCNTs radiolabeled with
111
In
(Fig. 9).
Furthermore, the particular features of carbon nanotubes make them good candidates to act as multimodal contrast agents with different imaging techniques.
4.2 Therapeutic Applications
Nanoparticles have revolutionized the field of drug delivery in the last two decades. Currently used therapeutic drugs suffer from low selectivity and low half-life,
making necessary it to give high doses to achieve the expected response, and thus
increasing undesirable side-effects. A proper and selective drug delivery system
would overcome most of these issues, and carbon nanotubes have been widely studied for this end [15].
As previously indicated, the nature of nanotubes permits a versatile chemistry allowing the attachment of drugs in a covalent or non-covalent manner with
an efficient drug-loading capacity. Besides, these nanostructures can be appropriately functionalized with different hydrophilic molecules to specifically recognize
the receptors overexpressed in the target cells, according to the alterations related
to the specific pathology to be treated [162]. So, the optimal functionalization of
CNTs make them promising drug-delivery systems in numerous therapies owing
to their achieved biocompatibility, suitable size, ability to penetrate the cells, and
196
Reprinted from the journal