Investigation of the Action of the Fullerene (C60) Derivatives on Mouse 3T3 Fibroblast Cell Lines

Abstract

Fullerene C60 is the third allotropic modification of carbon in nature. Exceptional physical and structural features of C60 molecule make it attractive for biomedical research in a wide spectrum of applications from imaging, drug delivery, to therapy of different disorders. However, its low solubility in water or polar solvents, and genotoxic potential represent serious barriers for its usage. To overcome mentioned limits the second derivative of fullerene C60 (Hyper harmonized hydroxylated fullerene water complex - 3HFWC) is created through functionalization of the first fullerene C60 derivative (fullerol - C60(OH)x) by the addition of paired OH groups in water layers surrounding the solid phase of substance. The solid phase consists of the C60 molecule, covalent OH groups and 3-6 water layers with strong hydrogen bonds. The liquid phase consists of additional water layers bonded by moderate to weak hydrogen bonds. In addition, the third derivative of fullerene is made when 3HFWC was integrated with nano-gold particles (nAu@3HFWC). The aim of this study was to evaluate fullerene C60 derivatives uptake and their intracellular distribution in mouse 3T3 fibroblasts. Cells were exposed to 30 μg/ml C60(OH)x, or 30 μg/ml 3HFWC, or 5μg/ml nAu@3HFWC during 30 min, 1h or 2h and analysis was done by Philips FEI CM12 transmission electron microscope. Ultrastructural analysis showed mainly cytoplasmic localization of C60(OH)x and its derivatives, and also a sporadic presence in mitochondria and nuclei. The concentration of fullerene derivatives in these cells was time-dependent, i.e., more concentration was observed in cells with longer exposition to these fullerenes. Furthermore, C60(OH)x is also localized in lysosomes in higher concentrations. These results suggest that novel C60 fullerene derivatives show better biocompatibility in mouse 3T3 fibroblasts compared to C60(OH)x, which mainly ends in lysosomes, the waste disposal system of the cell.