Cellular and in vitro toxicity of nanodiamond-polyaniline composites in mammalian and bacterial cell

The composite nanodiamond (ND) particles are rapidly emerging as promising material for the next generation agent for drug delivery, biosensors, or imaging contrast applications. Consequently, the health risks associated with the exposure to nanocomposite materials are utmost important. The objective of our work is to study the toxic effects of the nanodiamond-polyaniline (ND-Pani) composites in Human Embryonic Kidney (HEK) cell line. Toxic effects of either ND or ND-Pani nanocomposite in powder form on HEK293 are tested using MTT assay. Results indicated that there was no significant difference in the cell survival between samples treated with ND-Pani nanocomposite and the control sample for the two lower concentrations used in the experiments (p < 0.05). Morphology of the cells was not significantly affected due to the inclusion of nanocomposites during the incubation phase. The stability of the film was also improved due to the inclusion of the nanodiamond particles into the polymeric matrix making it suitable for electrochemical sensing applications. Experimental results have shown that the toxicity effect of lower concentration of ND-Pani composite is negligible, thus indicating that below 1 μg/ml could be a safer range without secondary toxicity effect.