Open Access Nano Express

Cytotoxicity Effects of Different Surfactant Molecules Conjugated to Carbon Nanotubes on Human Astrocytoma Cells

Lifeng Dong1*, Colette M Witkowski2, Michael M Craig2, Molly M Greenwade2 and Katherine L Joseph2

Author Affiliations

1 Department of Physics, Astronomy, and Materials Science, Missouri State University, Springfield, MO, 65897, USA

2 Department of Biomedical Sciences, Missouri State University, Springfield, MO, 65897, USA

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Nanoscale Research Letters 2009, 4:1517-1523  doi:10.1007/s11671-009-9429-0

Published: 4 September 2009

Abstract

Phase contrast and epifluorescence microscopy were utilized to monitor morphological changes in human astrocytoma cells during a time-course exposure to single-walled carbon nanotube (SWCNT) conjugates with different surfactants and to investigate sub-cellular distribution of the nanotube conjugates, respectively. Experimental results demonstrate that cytotoxicity of the nanotube/surfactant conjugates is related to the toxicity of surfactant molecules attached on the nanotube surfaces. Both sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) are toxic to cells. Exposure to CNT/SDS conjugates (0.5 mg/mL) for less than 5 min caused changes in cell morphology resulting in a distinctly spherical shape compared to untreated cells. In contrast, sodium cholate (SC) and CNT/SC did not affect cell morphology, proliferation, or growth. These data indicate that SC is an environmentally friendly surfactant for the purification and dispersion of SWCNTs. Epifluorescence microscopy analysis of CNT/DNA conjugates revealed distribution in the cytoplasm of cells and did not show adverse effects on cell morphology, proliferation, or viability during a 72-h incubation. These observations suggest that the SWCNTs could be used as non-viral vectors for diagnostic and therapeutic molecules across the blood–brain barrier to the brain and the central nervous system.

Keywords:
Carbon nanotubes; Surfactants; Cytotoxicity; Astrocytoma cells; Blood–brain barrier; Brain tumors; Central nervous system; Gene therapy; Non-viral gene vector