Interfacing Carbon Nanotubes with Living Mammalian Cells and Cytotoxicity Issues

Abstract

The unique structures and properties of carbon nanotubes (CNTs) have attracted extensive investigations for many applications, such as those in the field of biomedical materials and devices, biosensors, drug delivery, and tissue engineering. Anticipated large-scale productions for numerous diversified applications of CNTs might adversely affect the environment and human health. For successful applications in the biomedical field, the issue of interfacing between CNTs and mammalian cells in vitro needs to be addressed before in vivo studies can be carried out systematically. We review the important studies pertaining to the internalization of CNTs into the cells and the culturing of cells on the CNT-based scaffold or support materials. The review will focus on the description of a variety of factors affecting CNT cytotoxicity: type of CNTs, impurities, lengths of CNTs, aspect ratios, dispersion, chemical modification, and assaying methods of cytotoxicity.

Protein functionalized carbon nanomaterials for biomedical applications

“…Researchers have begun to undertake the task of examining the role of carbon nanotube chirality, curvature, and structure in its non-covalent interactions with the nanotube corona and the protein corona [152]. In addition, nanotoxicity concerns need to be addressed when aiming for applications involving biological cells, tissues, or animal models [153,154]. Finally, commercial viability of protein-carbon nanoparticle systems requires cost-effective synthesis and manufacturing, and competitiveness with regard to other commercially available products [21,154].…”

Delivery of drugs and biomolecules using carbon nanotubes

“…Different types of cell populations and assay methods may also lead to paradoxical findings. Various kinds of cell-viable indicator dyes, such as commassie blue, alamar blue, neutral red, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), and WST-1 (a watersoluble tetrazolium salt) [115], are used in the cytotoxicity studies as they can bind to CNTs and result in observable changes in the associated absorption/fluorescent emission, which correspond to the cytotoxic effect of CNTs. These can also lead to variability in the CNT cytotoxicity results.…”

Functionalized carbon nanotubes: biomedical applications

“…87 The solubility of CNTs can be increased through various methods of purification, which could also expose certain charged groups thereby, reducing cytotoxicity. 51 aqueous dispersions were found to be less toxic and more biocompatible than pristine CNTs in mice. 88 The uptake of acid-treated, water-soluble SWCNTs was studied using human monocyte-derived macrophage cells, and P-CNTs were found to be inside the lysosomes and cytoplasm without any effects on cell viability or structure compared to UP-CNTs.…”

“…50 Many studies have shown that increased solubility (or dispersion) of fCNTs improves their performance and lowers their toxicity (Table 1). 16,[51][52][53] These fCNTs have excellent electro-optical properties, high tensile strength, and a high surface-area-to-volume ratio that facilitates surface functionalization. 54 The addition of a layer of biocompatible material can be used to annihilate the toxicity of pristine CNT aggregates by making them more dispersible in aqueous solutions.…”