PARENT SESSION

WP6 Ecotoxicological Effects of Manufactured Nanomaterials
202 Oregon Ballroom
1:20 PM - 4:40 PM, Wednesday

() The differential cytotoxicity of water soluble fullerenes.

Sayes, C^{1, 2}, Fortner, J^{2, 3}, Lyon, D³, Boyd, A^{1, 2}, Ausman, K², Tao, Y⁴, Sitharaman, B¹, Wilson, L^{1, 2}, West, J^{2, 4}, Colvin, V^{1, 2}, ¹ Department of Chemistry, Rice University, Houston, Texas, USA² Center for Biological and Environmental Nanotechnology, Houston, Texas, USA³ Department of Environmental and Civil Engineering, Rice University, Houston, Texas, USA⁴ Department of Bioengineering, Rice Unviersity, Houston, Texas, USA

ABSTRACT- We show that the cytotoxicity of water soluble fullerene species are a sensitive function of their surface derivatization; in two different human cell lines, the lethal dose of fullerene changed over 8 orders of magnitude with relatively minor alterations in fullerene structure. In particular nano-C₆₀, the least derivatized of the four materials, was substantially more toxic than more highly soluble derivatives such as C₃, Na⁺_2-3 [C₆₀O_7-9(OH)_12-15]_(2-3)^-, and C₆₀(OH)₂₄. Oxidative damage to the cell membranes, but not to the internal organelles, was observed in all cases where fullerene exposure led to cell death. We show that under ambient conditions in water fullerenes can generate superoxide anions, and postulate these oxygen radicals are responsible for membrane damage. This work demonstrates both a strategy for enhancing the toxicity of fullerenes certain applications such as cancer therapeutics or bactericides, as well as a remediation for the possible unwarranted biological effects of pristine fullerenes.

Key words: toxicity, fullerene