Size-Dependent Toxicity of Nano-C₆₀ Aggregates: More Sensitive Indication by Apoptosis-Related Bax Translocation in Cultured Human Cells

Abstract

The toxicity of NPs is not well characterized in terms of their size. In particular, the size-based toxicity of fullerene (C(60)) remains an issue because of a lack of C(60) NPs with a well-controlled size. In this work, six fractions of the nano-C(60) aggregates (nC(60)) with different size distribution were prepared by a simple differential centrifugation. By using these nC(60) fractions, we demonstrate the size-dependent inhibition of DNA polymerase and reduced-size enhanced cytotoxicity. Above all, we found that nC(60) NPs with smaller size may have higher toxicity potency. These size-dependent effects were observed at the high exposure doses (4-6 mg/L). Interestingly, at 20-times lower and noncytotoxic doses, the size-dependent effect can be indicated by apoptosis-related fluorescent protein fused Bax translocation. Considering the toxicity of NPs is often ignored in the traditional end-point analysis for cytotoxicity when the exposure dose is low, the findings presented here will assist in the evaluation of the size-dependent cytotoxicity and dose-response relationships of toxicity mediated by nC(60) NPs at low doses.

A fullerene colloidal suspension stimulates the growth and denitrification ability of wastewater treatment sludge-derived bacteria

“…Our data indicate that the pH value, which has rarely been mentioned previously, is closely related to nC 60 biological activity. Low pH and high nC 60 concentrations promote the formation of nC 60 aggregates with larger diameters (Rudalevige et al, 1998;Fortner et al, 2005) and might subsequently attenuate nC 60 toxicity (Song et al, 2012). The biological effect of colloidal fullerene is to a large extent determined by environment factors.…”

Oxidative stress and immunotoxicity induced by graphene oxide in zebrafish

“…Though studies have shown that nanomaterials might have deleterious side effects (Nel et al, 2006;Song et al, 2012;Song et al, 2013), few reports on GO toxicity have been published so far. Akhavan and Ghaderi (2010) integrity upon exposure to GO (Tazawa et al, 2007) based on analysis by transmission electron microscopy (TEM).…”

Theoretical investigations on C60–ionic liquid interactions and their impacts on C60 dispersion behavior

“…The huge application potentials of these promising nanomaterials have strongly stimulated their production and consumption [2]. Inevitably, carbon nanoparticles (CNPs) have come into the environment [3,4] and have a strong possibility of posing health risks to human [5] and ecological species [6] because of their specific properties. The environmental health and safety risks of CNPs in society have thus become a serious concern in academia.…”