Authors: V.A. Agharkar, A. Bhushan, J.C.K. Lai, C.K. Daniels
Affilation: Idaho State University, United States
Pages: 122 - 125
Keywords: multi-wall carbon nanotubes, cytotoxicity, functionalization, signaling, apoptosis
The applications of carbon nanotubes (CNTs), a novel and important class of nanomaterials, can change paradigms of various research areas. Although biomedical applications of CNTs are increasing, their putative cytotoxicity has not been substantially addressed. We hypothesized that short multi-wall carbon nanotubes (MWNTs) induce cytotoxicity in different cell types and functional modifications of MWNTs alter cytotoxic response. We investigated this hypothesis using three different types of MWNTs namely, carboxylated (MWNT-COOH), hydroxylated (MWNT-OH) and non-functionalized MWNT. Our results indicate aqueous CNT suspension (3mg/ml) is toxic to cell lines of varying phenotypes; HFF-1, MCF-7, MCF-7Adr, and S180A10. Lactate dehydrogenase release studies indicate that necrosis is unlikely to account for decrease in survival induced by MWNT treatment. Internalization of CNTs may be a mechanism for apoptosis based on bright field microscopy images. S180A10 cells treated with three types of MWNTs (1mg/ml) induced decrease in phosphorylation of downstream signaling molecule Akt; non-functionalized MWNTs causing relatively stronger inhibition. These results support our hypothesis that short MWNTs are cytotoxic to cells with different phenotypes and functional modifications can alter these cytotoxic responses. Comprehensive cytotoxicity characterization of CNTs is critical to their development as novel drug delivery vehicles, diagnostic markers, and nanosensors in future.