Are Carbon Nanotubes a Natural Solution? Applications in Biology and Medicine

Abstract

Carbon nanotubes and materials based on carbon nanotubes have many perceived applications in the field of biomedicine. Several highly promising examples have been highlighted in the literature, ranging from their use as growth substrates or tissue scaffolds to acting as intracellular transporters for various therapeutic and diagnostic agents. In addition, carbon nanotubes have a strong optical absorption in the near-infrared region (in which tissue is transparent), which enables their use for biological imaging applications and photothermal ablation of tumors. Although these advances are potentially game-changing, excitement must be tempered somewhat as several bottlenecks exist. Carbon nanotube-based technologies ultimately have to compete with and out-perform existing technologies in terms of performance and price. Moreover, issues have been highlighted relating to toxicity, which presents an obstacle for the transition from preclinical to clinical use. Although many studies have suggested that well-functionalized carbon nanotubes appear to be safe to the treated animals, mainly rodents, long-term toxicity issues remains to be elucidated. In this report, we systematically highlight some of the most promising biomedical application areas of carbon nanotubes and review the interaction of carbon nanotubes with cultured cells and living organisms with a particular focus on in vivo biodistribution and potential adverse health effects. To conclude, future challenges and prospects of carbon nanotubes for biomedical applications will be addressed.

Electrode materials for microbial fuel cells: nanomaterial approach

“…CNT-based material Carbon nanotubes (CNTs), allotropes of carbon, have been shown to be promising alternative materials for MFC electrodes because of their unique electrical conductivity, chemical stability, biocompatibility, high specific area and also catalytic properties [36]. It is reported that CNTs have strong cell adhesion, cell attachment and growth properties [37,38]. Very recently, Erbay et al reported that microbes grown over CNTs result in excellent charge transfer characteristics due to p-p stacking between the carbon atoms of graphite and the pili (a cellular outgrowth) of microorganisms [39].…”

Multifunctional, biocompatible and pH-responsive carbon nanotube- and graphene oxide/tectomer hybrid composites and coatings

“…CNT/tectomer hybrids might also be of particular interest for controlled release of therapeutic and diagnostic agents, exploiting the cell penetrating capabilities of functionalized CNTs. 5,[104][105][106] It is known that tumoral tissues have a more acidic environment compared to healthy tissues. 107,108 As assembly/disassembly of tectomers is highly sensitive to pH modulation, these hybrids are promising candidates for site-specific controlled delivery of anticancer drugs.…”

“…[1][2][3][4][5][6][7] Such processes can be suitably controlled by tuning the experimental conditions such as pH, solvent, temperature and composition, offering new opportunities for designing smart, functional materials and odevices for a range of biomedical and technological applications. [8][9][10] Peptides, lipids, polynucleotides, polysaccharides, as well as polymers, gelators, and surfactants use these biomimetics to bind to and efficiently disperse carbon nanomaterials such as carbon nanotubes (CNTs) and graphene oxide (GO) in aqueous and biological media.…”

Two-color spectroscopy of UV excited ssDNA complex with a single-wall nanotube photoluminescence probe: Fast relaxation by nucleobase autoionization mechanism

“…SWNTs are inexpensive and robust in synthesis, chemically inert, mechanically stable, and biocompatible [14,15]. The existence of strong near infrared (NIR) SWNT bands that lie within the water transparency window make nanotubes remarkably suitable for bioimaging.…”

“…The existence of strong near infrared (NIR) SWNT bands that lie within the water transparency window make nanotubes remarkably suitable for bioimaging. Indeed, transient absorption microscopy, single-and two-photon fluorescence, Raman, and photo-thermal microscopy have been demonstrated both in vitro and in vivo [14,[16][17][18]. Due to the nanotube transverse size of a few nanometers (nm) and large aspect ratio up to 10 4 − 10 6 , controllable, in principle, by synthesis and/or post-processing, several applications in biological sensing have been achieved through direct mechanical, optical, and electronic interactions with biopolymers and cellular organelles of a similar size [19][20][21][22].…”