Carbon Nanotubes for Targeted Therapy: Safety, Efficacy, Feasibility and Regulatory Aspects.

Abstract: Multi-Wall Carbon Nanotubes (MWCNTs) are under investigation for their use in biomedical applications, especially in neurological diseases, due to their electrochemical properties. Nevertheless, conflicting results have cast doubt on their safety. To advance their translational potential, we evaluated the cytotoxicity of two MWCNT samples in vivo in both vertebrate and invertebrate animal models. Pristine MWCNTs were, in part, used as prepared (MWCNTs), and, in part, annealed at 2400 °C (a-MWCNTs). The two samples differ in their electrochemical properties: MWCNTs are not electro-conductive, while a-MWCNTs are electro-conductive and negatively charged on their surface. We evaluated the effects of both intranasally delivered MWCNTs on several key markers of cell viability in the olfactory bulbs and hippocampus from healthy adult Wistar rats, as well as their impact on lifespan, genotoxicity, oxidative stress, and aging-related functional markers in the nematode Caenorhabditis elegans. Neither of the two MWCNT samples was cytotoxic towards neuronal cells in the hippocampus. In olfactory bulbs, only electro-conductive a-MWCNTs interacted with two positively charged mitochondrial proteins: Translocase of Outer Mitochondrial Membrane 20 (TOM20) and Cytochrome C (CytC). In C. elegans, neither type of MWCNT affected lifespan or brood size, and cytosolic ROS levels remained unchanged. Notably, treated worms exhibited a significantly delayed aging phenotype. Metallic MWCNTs are biocompatible in living organisms and possess the potential to modulate neural cells functioning in vivo.

TL;DR: Graphite whiskers have been grown in a dc arc under a pressure of 92 atmospheres of argon and at 3900°K as discussed by the authors, with recoverable lengths up to 3 cm. They are embedded in a solid matrix of graphite which builds up by diffusion of carbon vapor from the positive to the negative electrode.

TL;DR: The synthesis of 4-cm-long individual single-wall carbon nanotubes at a high growth rate of 11 μm s−1 by catalytic chemical vapour deposition is reported, suggesting the possibility of growing SWNTs continuously without any apparent length limitation.

TL;DR: The potential of f-CNT to deliver different types of therapeutic molecules is described and stable covalent bonds or supramolecular assemblies based on noncovalent interactions are described.

TL;DR: The delivery of small molecule drugs is expounded, with special attention paid to the current progress of in vitro and in vivo research involving CNT-based DDSs, before finally concluding with some consideration on inevitable complications that hamper successful disease intervention with CNTs.