New study suggests pristine fullerene is non-toxic to cells

Posted: December 14, 2006
New study suggests pristine fullerene is non-toxic to cells
(Nanowerk News) A new method of application of C60 to cultured cells that does not require water solubilization techniques. Normal and malignant cells take-up C60 and the inherent photoluminescence of C60 is detected within multiple cell lines. Treatment of cells with up to 200µg/ml (200ppm) of C60 does not alter morphology, cytoskeletal organization, cell cycle dynamics nor does it inhibit cell proliferation. The work shows that pristine C60 is non-toxic to the cells, and suggests that fullerenebased nanocarriers may be used for biomedical applications.
Fullerene C60 molecules are unique for their multi-functional uses in materials science and optics, and are considered for a variety of biological applications, such as imaging probes, antioxidants and drug carriers. Realization of such goals requires a better understanding of the interactions between nanoparticles and cells and it is important to determine whether or not the particles by themselves impact cell growth and differentiation.
However, some undesirable properties of C60 present specific challenges. For example, due to its inherent hydrophobicity, C60 is poorly soluble and naturally forms large micron-sized clusters in aqueous media. Therefore, organic solvents are routinely used for solubilization of C60. Consequently, cell biological studies with pristine C60 have been limited.
The conflicting data on cytotoxic effects of C60 merits attention and requires a resolution if these materials are to become biologically useful. The following simple hypothesis may reconcile with the mutually contradictory data on the cytotoxic effects of pristine fullerenes. C60 undergoes modifications during the preparation of water soluble C60, and such changes are responsible for the cytotoxic effects.
Whereas the precise nature of such modifications is unknown at present, the hypothesis can be tested and the effects of C60 can be unequivocally examined if C60 can be applied to cells in such a way that obviates the need of preparing water soluble C60.
Studies presented in this new research examine the key issue of observed cytotoxic effects of C60 in cultured normal and malignant breast epithelial cells. We have developed a new, yet simple, method to directly apply C60 to cultured cells by modifying an established cell biological technique used in anoikis studies.
The paper, titled "C60-Fullerenes: Detection of intracellular photoluminescence and lack of cytotoxic effects" was published in the Journal of Nanobiotechlogy.



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