Chemical modification of SWNT alters in vitro cell‐SWNT interactions

Abstract

Single-walled carbon nanotubes (SWNT) have been the focus of considerable attention as a material with extraordinary mechanical and electrical properties. SWNT have been proposed in a number of biomedical applications, including neural, bone, and dental tissue engineering. In these applications, it is clear that surrounding tissues will come into surface contact with SWNT composites, and compatibility between SWNT and host cells must be addressed. This investigation describes the gross physical and chemical effects of different SWNT preparations on in vitro cell viability and metabolic activity. Three different SWNT preparations were analyzed: as purchased (AP-NT), purified (PUR-NT), and functionalized with glucosamine (GA-NT), over concentrations of 0.001-1.0% (wt/vol). With the exception of the lowest SWNT concentrations, increasing concentrations of SWNT resulted in a decrease of cell viability, which was dependent on SWNT preparation. The metabolic activity of 3T3 cells was also dependent on SWNT preparation and concentration. These investigations have shown that these SWNT preparations have significant effects on in vitro cellular function that cannot be attributed to one factor alone, but are more likely the result of several unfavorable interactions. Effects, such as destabilizing the cell membrane, soluble toxic contaminants, and limitations in mass transfer as the SWNT coalesce into sheets, may all play a role in these interactions. Using comprehensive purification processes and modifying the NT-surface chemistry to introduce functional groups or reduce hydrophobicity or both, these interactions can be significantly improved.

Diameter and rigidity of multiwalled carbon nanotubes are critical factors in mesothelial injury and carcinogenesis

“…Thus, nanotube toxicology should be evaluated differently than asbestos toxicology under certain conditions. Surface characteristics of MWCNTs, such as functionalization, degree of hydrophobicity, and protein modification, are thought to be important in internalization events (31,(42)(43)(44). The present study used pristine MWCNTs without any chemical functionalization and suspended MWCNTs in saline solution containing albumin as previously described (17).…”

Cytotoxicity induced by carbon nanotubes in experimental malignant glioma

“…Surface characteristics of functionalized MWCNTs, such as the degree of hydrophobicity and protein modification, are important for cell internalization. 20,44 Our study showed that nanoparticles functionalized with Fe were phagocytosed more efficiently, thus increasing their cellular damage. Similarly, Vakarelski et al reported that CNTs penetrate membranes of living cells.…”

Functionalized carbon nanotubes: biomedical applications

“…66 Glucosamine-functionalized SWCNTs were able to improve the interactions of the cells with SWCNTs. 67 A study conducted on HL60 cells using two types of fluorescent CNTs with FITC-CNTs and biotin submit your manuscript | www.dovepress.com…”

“…Functionalized CNT applications conjugates resulted in enhanced membrane translocation with reduced cytotoxicity, 67 and another study also indicated the internalization of fluorescently labeled nanotubes into cells with no apparent toxicity. 68 Similarly, a study conducted on immune-system cells using two classes of fCNTs -one with 1,3-dipolar cycloaddition and another with oxidation/ amidation -showed that both types of fCNTs were taken up by B and T lymphocytes as well as by macrophages in vitro without affecting cell viability.…”