Comparative Toxicity of C_(60) Aggregates toward Mammalian Cells: Role of Tetrahydrofuran (THF) Decomposition

摘要

C_(60) fullerene is a promising material because of its unique physiochemical properties. However, previous studies have reported that colloidal aggregates of C_(60) (nC_(60)) produce toxicity in fish and human cell cultures. The preparation method of nC_(60) raises questions as to whether the observed effects stem from fullerenes or from the organic solvents used during the preparation of the suspensions. In this paper, we set out to elucidate the mechanism by which tetrahydrofuran (THF) treatment to enhance the preparation of nC_(60) leads to cytotoxicity in a mouse macrophage cell line. Our results demonstrate that THFC_(60) but not fullerol or aqueous nC_(60) generates cellular toxicity through a pathway that involves increased intracellular flux and mitochondrial perturbation in RAW 264.7 cells. Interestingly, the supernatant of the THFC_(60) suspension rather than the colloidal fullerene aggregates mimics the cytotoxic effects due to the presence of γ-butyrolactone and formic acid. Thus, the role of nC_(60) in the cellular responses is likely not due to the direct effect of the nC_(60) material surface on the cells but is related to the conversion of THF into a toxic byproduct during preparation of the suspension.