Suppression of Proinflammatory Cytokines in Functionalized Fullerene-Exposed Dermal Keratinocytes

Initial experiments using differentially functionalized fullerenes, CD-C-60, hexa-C-60, and tris-C-60, suggested a properties dependent effect on cytotoxic and proliferative responses in human skin keratinocytes. In the present study we investigated the cytokine secretion profile of dermal epithelial cells exposed to functionalized fullerenes. Keratinocyte-derived cytokines affect homing and trafficking of normal and malignant epidermal immune as well as nonimmune cells in vivo. These cytokines are critical for regulating activation, proliferation, and differentiation of epidermal cells. Our results indicate that tris-C-60 (size range < 100 nm) significantly reduces inflammatory cytokine release in a dose- and time-dependent manner. In contrast CD-C-60 demonstrated a relatively pro-inflammatory cytokine response, while hexa-C-60 did not significantly perturb cytokine responses. Physical and chemical characterizations of these engineered nanomaterials suggest that the disparate biological responses observed may potentially be a function of the aggregation properties of these fullerenes.