Investigation of Toxicological and Functionalized Formulation of Carbon Nanotubes

Abstract

Nicholas Seifalian, Emma Oreskovic and Seyed Yazdan Madani

Carbon nanotubes (CNTs) are emerging technology for biomedical application, including facilitating feasible drug delivery, non-invasive treatment modalities, scaffold for regenerative medicine and more. However, impeding the clinical translation of such products is CNT toxicity, which has unfavourable consequences at the cellular level. CNT toxicity is onset by factors including CNT nanoscale size, which is associated with increased reactivity, its fibrous nature which promotes inflammatory responses, and its graphitic structure, linked to poor physiological elimination and toxic buildup. To assess how CNT toxicity could be minimised in-vitro, this study analysed two different lengths of single-walled carbon nanotubes (SWCNTs), altering their concentration, functionalization levels, and exposure period to cell lines MCF7 and HT29. Toxicity was assessed by analysing cell viability and DNA concentration using Alamar Blue and DNA assays, respectivel reduction of the metabolic actitivity and DNA concentration following the exposure of both MCF7 and HT29 to short and long pristine SWCNT was observed.

In this experiment the thickness of both short and long SWCNT was in the similar range. However, functionalization resulted in the SWCNT to become ticker, which could be one possible reason of reducing the CNT’s toxicity. This is because the CNT functionalization leads to lower chance of SWCNT entering the nucleus and interrupting normal DNA functions. With regards to the length of the SWCNT, the result shows that the long SWCNT is more toxic than the short SWCNT. It was demonstrated that short SWCNTs functionalized for a longer duration were significantly linked to less toxicity (P<0.05). Implementing this strategy in reduction of SWCNT’s toxicity is one way of improving the potentional application of CNT in clinical area. The application of nanoparticles for drugs, genes and vaccines is a multi-billion-dollar industry with great interest to clinicians and pharmaceutical industries, being considered as an emerging technology.

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