Stable Colloidal Dispersions of C₆₀ Fullerenes in Water: Evidence for Genotoxicity

Abstract

Stable aqueous suspensions of colloidal C60 fullerenes free of toxic organic solvents were prepared by two methods: ethanol to water solvent exchange (EthOH/nC60 suspensions) and extended mixing in water (aqu/nC60 suspensions). The extended mixing method resulted in the formation of larger (dp approximately 178 nm) and less negatively charged (zeta approximately -13.5 mV) nC60 colloids than nC60 prepared by ethanol to water solvent exchange (dp approximately 122 nm, zeta approximately -31.6 mV). Genotoxicity of these suspensions was evaluated with respect to human lymphocytes using single-cell gel electrophoresis assay (Comet assay). The assay demonstrated genotoxicity for both types of suspensions with a strong correlation between the genotoxic response and nC60 concentration, and with genotoxicity observed at concentrations as low as 2.2 microg/L for aqu/nC60 and 4.2 microg/L for EtOH/nC60. The Olive tail moments (OTM) for these two concentrations were 1.54 +/- 0.24 and 1.34 +/- 0.07, respectively, which in comparison to the negative control OTM of 0.98 +/- 0.17 is statistically different with a p value of at least 0.05. Aqu/nC60 suspensions elicited higher genotoxic response than EthOH/nC60 for the same nC60 concentration. The results represent the first genotoxicity data for colloidal fullerenes produced by simple mixing in water.

In vitro and in vivo toxicity assessment of nanoparticles

“…In vitro studies on silver nanoparticles' toxicity have suggested that interference with DNA replication, fidelity, apoptosis, oxidative stress, cytotoxicity, chromosome instability, intracellular calcium transients, JNK activation and cell cycle arrest in mammalian cells [121-125, 140, 141]. Fullerenes are responsible for DNA damage and oxidative stress in mammalian cells lines [142][143][144]. In a study on FE1-Muta™ mouse lung, epithelial cells were investigated to observe the effects of C 60 fullerenes and SW-CNTs for cytotoxicity, genotoxicity and ROS production [142].…”

Photophysical Properties of C60 Colloids Suspended in Water with Triton X-100 Surfactant: Excited-State Properties with Femtosecond Resolution

“…Many authors have reported on the photophysical properties of molecular solutions of C 60 . [12][13][14][15][16][17][18][19][20] Likewise, many authors have studied the photophysical and structural properties of solid films of C 60 . [21][22][23][24][25][26][27][28][29][30][31][32][33][34] Under certain conditions, C 60 forms stable colloidal assemblies in solvents.…”

“…[12][13][14][15][16][17][18][19][20] Likewise, many authors have studied the photophysical and structural properties of solid films of C 60 . [21][22][23][24][25][26][27][28][29][30][31][32][33][34] Under certain conditions, C 60 forms stable colloidal assemblies in solvents. [35][36][37][38][39][40][41][42][43][44] Colloidal suspensions of C 60 particles can also be formed in binary solvent mixtures, in which one is a good solvent and the other is a poor solvent for C 60 .…”

“…[21][22][23][24][25][26][27][28][29][30][31][32][33][34] Under certain conditions, C 60 forms stable colloidal assemblies in solvents. [35][36][37][38][39][40][41][42][43][44] Colloidal suspensions of C 60 particles can also be formed in binary solvent mixtures, in which one is a good solvent and the other is a poor solvent for C 60 . [45][46][47][48][49] Aqueous suspensions of colloidal C 60 particles are also formed by a number of methods, [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64] including solubilization in micellar solutions.…”

C60 affects DNA replication in vitro by decreasing the melting temperature of DNA templates

“…By using atomistic molecular dynamics simulations, Zhao et al [19] demonstrated that C 60 could strongly bind to nucleotides, suggesting that C 60 molecules have a potentially negative impact on the structure, stability, and biological functions of DNA molecules. Recently, the possible genotoxicity of C 60 was demonstrated by using single-cell gel electrophoresis assay [20].…”