Biodistribution of Carbon Nanotubes in Animal Models

Abstract

The many interesting physical and chemical properties of carbon nanotubes (CNT) make it one of the most commercially attractive materials in the era of nanotechnology. Here, we review the recent publications on in vivo biodistribution of pristine and functionalized forms of single-walled and multi-walled CNT. Pristine CNT remain in the lung for months or even years after pulmonary deposition. If cleared, the majority of CNT move to the gastrointestinal (GI) tract via the mucociliary escalator.However, there appears to be no uptake of CNT from the GI tract, with a possible exception of the smallest functionalized SWCNT. Importantly, a significant fraction of CNT translocate from the alveolar space to the near pulmonary region including lymph nodes, subpleura and pleura (<7% of the pulmonary deposited dose) and to distal organs including liver, spleen and bone marrow (~1%). These results clearly demonstrate the main sites of long-term CNT accumulation, which also includes pleura, a major site for fibre-induced pulmonary diseases. Studies on intravenous injection show that CNT in blood circulation are cleared relatively fast with a half-life of minutes or hours. The major target organs were the same as identified after pulmonary exposure with the exception of urine excretion of especially functionalized SWCNT and accumulation in lung tissue. Overall, there is evidence that CNT will primarily be distributed to the liver where they appear to be present at least one year after exposure.

Gadolinium‐containing carbon nanomaterials for magnetic resonance imaging: Trends and challenges

“…The patter agrees with those reported for fullerenes and carbon nanotubes. For example, it was reported that long carbon nanotubes are mainly accumulated in lungs, Avti et al observed the same patter for gadonanotubes of 500 nm to 1.5 mm of length, by contrast. Also, it is well‐known small carbon nanotubes can be accumulated in bladder and kidneys, Marangon et al observed the functionalized gadonanotubes with average length of ≈400 nm, were mainly accumulated in bladder and kidneys.…”

“…This long‐term accumulation may represent a risk. A number of reports have found pristine CNTs remain in lungs for months or even years after pulmonary deposition, even more, the accumulation is associated with chronic inflammation and tissue damage . Particularly, the accumulation of MWCNTs in lungs is associated with fibrotic‐like lesions via non‐resolved chronic inflammation and the chronic exposure to SWCNTs may cause malignant transformation of human lung epithelial cells and induced tumorigenesis in mice .…”

“…As can be appreciated, carbon nanotubes and fullerenes are associated with toxic effects, however, also a number of reports have found the functionalization with functional groups, polymers and biomolecules may modulate the biodistribution and elimination . Carboxylic acid‐functionalized fullerenes have exhibited high levels of retention (even 72 hours after intravenous administration) in contrast hydroxyl‐functionalized fullerenes are rapidly excreted in urine .…”

Recent Advance in Near‐Infrared (NIR) Imaging Probes for Cancer Theranostics

“…[34] Saito and coworkers evaluated the pharmacokinetics of heavy metal-doped SWNTs in vivo using an advanced in situ MRI technique. [34] Saito and coworkers evaluated the pharmacokinetics of heavy metal-doped SWNTs in vivo using an advanced in situ MRI technique.…”

Fatal Ethylene Glycol Intoxication Secondary to Accidental Ingestion

“…In the same time ADH is the therapeutic target in blocking ethylene glycol metabolising pathway by using ethylic alcohol as a powerful competitor for binding to the enzyme as its affinity is 67 times higher for ethanol compared to ethylene glycol [4]. The metabolic products of ethylene glycol are: glycoaldehyde, glycolic acid, glyoxylic acid, oxalic acid and calcium oxalate.…”