Length-dependent uptake of DNA-wrapped single-walled carbon nanotubes

Well-dispersed, separated length fractions by SEC, the exhaustive characterization of these fractions, and high concentration in toxicity data, which indicate a threshold on the length and corresponding toxicity of single-walled carbon nanotubes (SWNT)was investigated. An assay was used to look for reductions in metabolic activity of the cell population upon exposure to the DNA wrapped SWNTs. Photometric quantification was performed at 450 nm, and the results were given in percent as relative values to the negative control, wherein the untreated (negative) control was set to be 100 % viable. Extraction of the supernatants (50 ttL each) from the 96-well plates revealed that measurable quantities of the original tube populations remained in solution, indicating incomplete uptake of the SWNTs by the cells. These results support the length-dependent uptake hypothesis and suggest that shorter tubes may therefore be more toxic to cells than longer SWNTs.

Duke Scholars

Author Matthew L Becker Chemistry